Hollow connected body and packaging material

ABSTRACT

This invention relates to a connected hollow structure and a packaging member suitable for use as a cushioning material, a protection frame material, a core material of a hollow panel and a carrier for carrying adsorbents. A connected hollow structure comprises a large number of hollow structures  10  having an arbitrary sectional shape and connected in parallel to each other. The connected hollow structure is formed from a piece of sheet and takes the shape resembling a unicursal figure in section. It is possible to form a connected hollow structure which shows elasticity and withstanding strength fit for the purpose and also has a smaller apparent specific gravity by properly selecting the quality of a sheet a, and the sectional shape and size of the hollow structures  10.

TECHNICAL FIELD

This invention relates to a connected hollow structure having a largenumber of parallel hollow portions of a predetermined sectional shape,and a packaging member.

BACKGROUND ART

Corrugated fiberboards are, for instance, typical of a conventionalmember fabricated from paper sheets having hollow portions parallel toone another.

The corrugated fiberboards are classified into A to E-flute corrugatedfiberboards according to the size of flutes, and also classified into asingle faced corrugated fiberboard, a double faced corrugatedfiberboard, a double wall corrugated fiberboard and a triple wallcorrugated fiberboard according to differences in structure.

These corrugated fiberboards are used for forming packaging boxes,cushioning materials and other packaging members. Recently, a proposalhas been made that a layered corrugated fiberboard be used for formingcushioning materials for packaging, frame structures for packaging, andcore materials of heat-insulating panels or the like.

The corrugated fiberboard and the layered corrugated fiberboard memberas described above have the following problems.

Namely, one of the problems is that the corrugated fiberboard must befabricated by the use of base boards, and as a result, it is notpossible to freely select a material (i.e., base board) for thecorrugated fiberboard.

Another problem is that since the corrugated fiberboard is astandardized product, there are restrictions on selection of voidcontent (which means a ratio of the sectional area of hollow portions tothe whole sectional area in a section crossing at a right angle to thehollow portions) for the corrugated fiberboard.

A further problem is that it is not possible to freely select asectional shape for the hollow portions.

In connection with the above problems, a still further problem is thatcushioning materials, packaging frame structures and other packagingmembers which are formed by the use of layered corrugated fiberboardsare limited in selection of their hardness or the strength of elasticityfrom the viewpoint of design. Coincidentally, this problem means thattheir use is restricted within narrow limits.

A yet further problem is that several pieces of base boards andlinerboard, and besides, a large number of steps, are required forfabricating a corrugated fiberboard, and as a result, high fabricationcost is inevitable.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a connected hollowstructure, in which its material may be more freely selected accordingto intended purpose (use), and a packaging member comprised of such aconnected hollow structure.

Another object of the present invention is to provide a connected hollowstructure, in which its void content may be freely designed according tothe intended purpose, and a packaging member comprised of such aconnected hollow structure.

A further object of the present invention is to provide a connectedhollow structure, for which the sectional shape of hollow portions maybe freely selected according to the intended purpose, and a packagingmember comprised of such a connected hollow structure.

A still further object of the present invention is to provide aconnected hollow structure, in which its hardness and the strength ofelastic force and withstanding strength may be selected more freelyaccording to the intended purpose, in cooperation with the selection ofthe material and the freedom of design of the void content and thesectional shape of hollow portions, and a packaging member comprised ofsuch a connected hollow structure.

A yet further object of the present invention is to provide a connectedhollow structure, which is fabricated through fewer steps by the use ofa piece of sheet, to which various kinds of materials are applied, and apackaging member comprised of such a connected hollow structure.

A yet further object of the present invention is to provide a connectedhollow structure which may be used for a variety of purposes.

In order to attain the above objects, a connected hollow structureaccording to the present invention is formed as follows.

According to a first embodiment of the present invention, a large numberof hollow structures of an arbitrary sectional shape are connected inparallel to each other, and the connected hollow structure is comprisedof a sheet and takes a shape resembling a unicursal figure in section.

The sheet may be freely selected from a group consisting of ordinarysheets, water-resistant sheets, coated printing sheets having coatedsurfaces, laminated sheets, styrene paper (formed by solidifying anon-woven fabric into a sheet-like shape by means of heating or using aresin, for instance), hard or semi-hard plastic sheets, thick paper,corrugated fiberboards, thin plywood and so on.

The hollow structures adjacent to each other are bonded together with anadhesive or connected or joined together directly or indirectly throughother means.

The connected hollow structure in the first embodiment has cushioningproperties depending on the quality of the sheet selected as thematerial of the connected hollow structure or the sectional shape andapparent specific gravity (i.e., void content) of the hollow structures,since the hollow structures are deformed when an external force isapplied to the connected hollow structure in a direction crossing eachhollow structure. The connected hollow structure of the first embodimentis suitable for use as a cushioning material, a packaging framestructure or like packaging member by making use of its elasticitydepending on the sectional shape of the hollow structures, and besides,may be used for various purposes by making use of the hollow structures.

Thus, it is possible to fabricate a connected hollow structure, whichhas an apparent specific gravity (void content) suitable for theintended purpose and which shows the withstanding strength or elasticitysuitable for the purpose, by freely selecting the shape and sectionalarea of the hollow structures and the quality of the sheet, as describedabove.

Further, since the connected hollow structure takes the shape resemblinga unicursal figure in section and is comprised of a single sheet, it ispossible to fabricate the connected hollow structure through fewer stepsat low cost.

Furthermore, the connected hollow structure is designed more freely, andtherefore, may be used for a variety of purposes.

In a second embodiment of the present invention, the hollow structuresinclude first and second hollow structures each having a corner portionof a convex angular section. Each first hollow structure having thecorner portion directed toward one surface of the connected hollowstructure and a partial circumference facing the other surface of theconnected hollow structure and each second hollow structure having thecorner portion directed toward the other surface of the connected hollowstructure and a partial circumference facing one surface of theconnected hollow structure, are formed in an alternate arrangement, andthe first and second hollow structures adjacent to each other share incommon at least a part of side walls, which include each corner portion.

The connected hollow structure in the second embodiment is easilypatterned according to the intended purpose by selecting the sectionalshape and size of the hollow structures, since the first and secondhollow structures are formed in an alternate arrangement such that thecorner portion of each first hollow structure is directed to besubstantially reverse to that of each second hollow structure.

Further, the first and second hollow structures are formed in a densearrangement, since the first and second hollow structures adjacent toeach other share in common at least a part of the side walls, whichinclude the corner portion of each hollow structure. Therefore, theconnected hollow structure in the second embodiment is suitable for useas not only a packaging member, but also as a core material of aheat-insulating panel or like panel and as a carrier for carryingadsorbents by forming a layered connected hollow structure such that thehollow structures are in parallel with each other.

Furthermore, the hollow structures are easily connected together througha mechanical means by joining or connecting the first hollow structurestogether in a portion of the corner portion of each second hollowstructure positioned between the adjacent first hollow structures orjoining or connecting the second hollow structures together in a portionof the corner portion of each first hollow structure positioned betweenthe adjacent second hollow structures.

In a third embodiment of the present invention, the first and secondhollow structures have a polygonal section, and the connected hollowstructure is formed by folding the sheet along folds formed on thesheet.

Therefore, the connected hollow structure in the third embodiment ispatterned more easily, and also formed by machining more easily.

Further, it is possible to fabricate a connected hollow structure whichtakes various shapes according to the purpose by properly selecting thesectional shape of the hollow structures.

In a fourth embodiment of the present invention, the first and secondhollow structures in portions other than at least both ends of theconnected hollow structure have a polygonal section including sides ofthe same number. with the connected hollow structure of the fourthembodiment, it is possible to design a connected hollow structure whichtakes various shapes according to the purpose, such as a connectedhollow structure, in which hollow structures have a similar ornon-similar sectional shape. Otherwise, a connected hollow structurewhich is uniform in apparent thickness on the whole, and has acylindrical shape, a gutter-like shape, a channel-like shape or the likemay be designed by properly selecting the sectional size of the hollowstructures. Further, since the sides included in the sectional shape ofthe first and second hollow structures are of the same number, theconnected hollow structure in the fourth embodiment is formed bymachining more easily.

Connected hollow structures in fifth to eighth embodiments of thepresent invention are typical of the connected hollow structure in thefourth embodiment.

Namely, according to the connected hollow structure in the fifthembodiment, the first and second hollow structures have a triangularsection.

According to the fifth embodiment, since the hollow structures have apolygonal section including the fewest sides, it is the easiest to formthe folds on the sheet and to fold the sheet by machining, and it ispossible to fabricate a connected hollow structure most efficiently.

According to the connected hollow structure in the sixth embodiment ofthe present invention, the first and second hollow structures have anisosceles triangular or right-angled triangular section.

With the sixth embodiment, it is possible to fabricate a panel-shapedconnected hollow structure, which is uniform in apparent thickness ofeach portion, by designing the first and second hollow structures, forinstance, so as to have the isosceles triangular section, to be of thesame sectional size, and to be arranged such that the base surfaces ofthe first and second hollow structures respectively face opposingsurfaces of the connected hollow structure. Since a planar pressure actson the connected hollow structure, mainly on two equal side walls ofeach hollow structure, the connected hollow structure shows withstandingstrength against the planar pressure more uniformly in each portion ofthe connected hollow structure. Further, when the connected hollowstructure is exposed to a relatively high planar pressure, the hollowstructures are transformed such that two same-sized and angled sidewalls of the hollow structures are bent. Thus, the connected hollowstructure shows elasticity against the planar pressure substantiallyuniformly in each portion of the connected hollow structure.

Further, with the sixth embodiment, it is possible to fabricate aconnected hollow structure, which is uniform in apparent thickness ofeach portion and has a cylindrical shape on the whole or asemicylindrical channel-like shape, by designing the first and secondhollow structures so as to have the isosceles triangular section, to beof the same height in section and to form the base surface of each firsthollow structure narrower than that of each second hollow structure(i.e., to intersect two equilateral surfaces at a small angle).

Furthermore, with the sixth embodiment it is possible to fabricate apanel-shaped connected hollow structure, which is uniform in apparentthickness of each portion, by designing the first and second hollowstructures so as to have the right-angled triangular section, to be ofthe same sectional size, and to be arranged such that one of the sidesurfaces including a right angle faces each surface of the connectedhollow structure. In this case, a planar pressure acts on the connectedhollow structure, mainly on vertical side walls and inclined side wallsof the hollow structures. However, the connected hollow structure showshigh withstanding strength against the planar pressure, since thevertical side walls of the hollow structures are arranged atpredetermined intervals.

In the connected hollow structure of the seventh embodiment the firstand second hollow structures have a quadrangular or pentagonal section.Thus, it is possible to fabricate a connected hollow structure whichtakes various shapes according to the intended purpose, such as aconnected hollow structure which has a panel-like shape with uniformthickness of each portion, or a cylindrical shape, a channel-like shape,a gutter-like shape or the like, by designing the first and secondhollow structures to have a special section.

In the connected hollow structure of the eighth embodiment, the firstand second hollow structures have a hexagonal or more polygonal section.Thus, each hollow structure of the connected hollow structure in theeighth embodiment has a large number of side surfaces and when the sidesurfaces of the hollow structures are of the same size, the connectedhollow structure shows high withstanding strength against an externalforce applied to the hollow structures in the length direction. Further,this connected hollow structure shows more flexible elasticity against aplanar pressure, since, when the connected hollow structure is exposedto a planar pressure, the hollow structures are transformed and absorbsuch a planar pressure. Furthermore, this connected hollow structure issuitable for use as a frame structure for packaging rod-shaped articlessuch as linear fluorescent lamps by inserting such articles into thehollow structures, for instance.

In a ninth embodiment of the present invention, the first and secondhollow structures, in portions other than at least both ends of theconnected hollow structure, have a polygonal section including sides ofthe same number, and the polygonal section of the first hollowstructures is different from that of the second hollow structures innumber of sides.

Connected hollow structures in tenth and eleventh embodiments of thepresent invention are typical of the connected hollow structure in theninth embodiment.

In a tenth embodiment, either the first or second hollow structures havea triangular section, and the others have a quadrangular or pentagonalsection.

In an eleventh embodiment, either the first or second hollow structureshave a quadrangular section, and the others have a pentagonal section.

According to the tenth and eleventh embodiments, it is possible tofabricate a connected hollow structure which takes various shapesaccording to the purpose, such as a connected hollow structure which hasa panel-like shape with uniform thickness in each portion, or acylindrical shape, a channel-like shape, a gutter-like shape or thelike, by designing the first and second hollow structures so as to havea special section, and by properly selecting the sectional size of thesehollow structures.

A twelfth embodiment of the present invention is a modification of thethird embodiment wherein either the first or second hollow structures inportions other than at least both ends of the connected hollow structurehave a polygonal section including sides of the same number, and theothers include hollow structures respectively having polygonal sectionsdifferent in number of sides.

Connected hollow structures in thirteenth and fourteenth embodiments ofthe present invention are typical of the connected hollow structure inthe twelfth embodiment.

In the connected hollow structure of the thirteenth embodiment, eitherthe first or second hollow structures have a triangular section, and theothers include hollow structures having a quadrangular section and thosehaving a pentagonal section.

In the connected hollow structure of the fourteenth embodiment, eitherthe first or second hollow structures have a triangular section, and theothers include hollow structures having a triangular section and thosehaving a pentagonal section.

With the thirteenth and fourteenth embodiments, it is possible tofabricate a connected hollow structure which takes various shapesaccording to the intended purpose, such as a connected hollow structurewhich has a panel-like shape with uniform thickness in each portion, ora cylindrical shape, a channel-like shape, a gutter-like shape or thelike, by designing the others of the first and second hollow structuresto have a special section, and by properly selecting the sectional sizeof the hollow structures.

In a fifteenth embodiment of the present invention, the first and secondhollow structures in portions other than at least both ends of theconnected hollow structure include hollow structures respectively havingpolygonal sections different in number of sides.

Connected hollow structures in sixteenth and seventeenth embodiments ofthe present invention are typical of the connected hollow structure inthe fifteenth embodiment.

In the sixteenth embodiment, the first and second hollow structuresinclude hollow structures having a triangular section and those having aquadrangular or pentagonal section.

In the seventeenth embodiment, the first and second hollow structuresinclude hollow structures having a quadrangular section and those havinga pentagonal section.

With the sixteenth and seventeenth embodiments, it is possible tofabricate a connected hollow structure which takes various shapesaccording to the intended use, such as a connected hollow structurewhich has a panel-like shape with uniform thickness in each portion, ora cylindrical shape, a channel-like shape, a gutter-like shape or thelike, by designing the hollow structures other than those having thetriangular section to have a special section, and by properly selectingthe sectional size of the hollow structures.

The connected hollow structure of an eighteenth embodiment of thepresent invention is a modification of the connected hollow structure inany of the fifth, seventh, tenth, thirteenth, fourteenth, sixteenth andseventeenth embodiments, wherein one side surface of the first andsecond hollow structures in portions other than at least both ends ofthe connected hollow structure forms the partial circumferences (i.e.,partial circumferences facing opposite surfaces of the connected hollowstructure) of the first and second hollow structures described above.

The connected hollow structure in the eighteenth embodiment has anadvantage in being fabricated without forming irregularities on thesurface.

A nineteenth embodiment of the present invention is a modification ofthe eighteenth embodiment wherein the partial circumferences of thefirst hollow structures and those of the second hollow structures arerespectively connected together, and the connected hollow structure hasa panel-like shape substantially uniform in apparent thickness.

The connected hollow structure of the nineteenth embodiment has opposingsubstantially smooth surfaces and a panel-like shape, and therefore, issuitable for use as a packaging member for packaging articles, and as acore material of a heat-insulating panel or like hollow panel.

The twentieth embodiment of the present invention is a modification ofthe eighteenth embodiment, wherein the partial circumferences of thefirst hollow structures and those of the second hollow structures arerespectively connected together, and the connected hollow structure hasa cylindrical or gutter-like overall shape.

The connected hollow structure in the twentieth embodiment is suitablefor use as a frame structure for packaging bottles or like articleshaving a rod-shaped drum portion.

In a twenty-first embodiment of the present invention, the connectedhollow structure of the eighteenth embodiment is modified so that thepartial circumferences of the first hollow structures and those of thesecond hollow structures are respectively connected together, and theconnected hollow structure has a rising portion formed at least on onesurface so as to gradually rise from one portion to the other.

The connected hollow structure of the twenty-first embodiment issuitable for use as a member for packaging an article by forming therising portion on one surface so as to be fit for the external shape ofthe article, for instance.

The connected hollow structure of a twenty-second embodiment of thepresent invention is a modification of the connected hollow structure inthe twenty-first embodiment wherein a pitch of the first and secondhollow structures formed in the rising portion is made smaller inproportion to the scale of rising. In the connected hollow structure ofthe twenty-second embodiment, since the pitch of the hollow structuresformed in the rising portion is small, the withstanding strength againsta planer pressure applied to the rising portion is easily made uniformwith that against the planar pressure applied to a portion other thanthe rising portion.

A twenty-third embodiment of the present invention is a modification ofany of the nineteenth, twenty-first and twenty-second embodimentswherein the hollow structure positioned at both ends of the connectedhollow structure has a chamfered inclined side surface extending in thelength direction of the hollow structure. In this embodiment, the hollowstructure positioned at opposing ends of the connected hollow structurehas the chamfered inclined side surface, and therefore, even whenanother object contacts the chamfered surface of the connected hollowstructure, neither the other object or the chamfered surface of theconnected hollow structure is damaged.

The a twenty-fourth embodiment of the present invention is amodification of the eighteenth embodiment wherein the connected hollowstructure has a projection formed at least on one surface so as toextend parallel to the length of the hollow structures, and the partialcircumferences of the first or second hollow structures in theprojection are connected together. The twenty-fourth embodiment is veryconvenient for use as a packaging member for packaging an article byforming the projection so as to fit a concave surface of the article.

The twenty-fifth embodiment of the present invention is a modificationof the connected hollow structure of the twenty-fourth embodimentwherein the connected hollow structure has a plurality of projections,and a portion between the projections is formed into a channel-likeportion. The connected hollow structure of the twenty-fifth embodimentis suitable for use as a packaging member for packaging an article byinserting such an article wholly or partially into the channel-likeportion.

The twenty-sixth embodiment of the present invention is a modificationof the connected hollow structure of the twenty-fourth or twenty-fifthembodiment wherein a pitch of the first and second hollow structuresformed in the projection is made smaller than that of the remainder ofthe first and second hollow structures. The connected hollow structureof the twenty-sixth embodiment, since the pitch of the hollow structuresformed in the projection is small, has a withstanding strength against aplanar pressure applied to the projection which is easily made uniformwith that against the planar pressure applied to the remainder of thestructure.

The twenty-seventh embodiment of the present invention is a modificationof the connected hollow structure in any of the twenty-fourth totwenty-sixth embodiments, the hollow structure, at the opposing ends ofthe projection, has a chamfered inclined side surface extending parallelto the length of the hollow structure. In this embodiment, the hollowstructure, at opposing ends of the projection of the connected hollowstructure of the twenty-seventh embodiment has the chamfered inclinedside surface, and therefore, even when another object is brought intocontact with the chamfered surface of the connected hollow structure,neither the other object nor the chamfered surface of the connectedhollow structure is damaged. In addition, the chamfered surfacefunctions as a guide for articles to be packaged.

The twenty-eighth embodiment of the present invention is a modificationof the connected hollow structure in any of the nineteenth totwenty-seventh embodiments wherein all or part of at least either thefirst or second hollow structures have surfaces in the form a circulararc facing the surface of the connected hollow structure, and therefore,when this connected hollow structure receives a planar force, thecircular arc surfaces of the hollow structures provide elasticity(cushioning properties) and partially absorb the planar force.

In the twenty-ninth embodiment of the present invention, a modificationof the connected hollow structure of the third embodiment, all or partof at least either the first or second hollow structures have aplurality of side surfaces substantially uniformly projecting from onesurface of the connected hollow structure, and the hollow structureshave a quadrangular or more polygonal section. Therefore, when theconnected hollow structure receives a planar force, the side surfacesare transformed and partially absorb such a force.

In a thirtieth embodiment of the present invention, a modification ofthe connected hollow structure of the twenty-ninth embodiment, the firsthollow structures and the second hollow structures have longitudinalsurfaces respectively connected together, and the connected hollowstructure has a panel-like shape substantially uniform in apparentthickness. Therefore, this thirtieth embodiment is suitable for use as amember for packaging articles, and as a core material of aheat-insulating panel or like hollow panel.

In a thirty-first embodiment of the present invention, a modification ofthe connected hollow structure of the twenty-ninth embodiment,longitudinal surfaces of the first hollow structures and of the secondhollow structures are respectively connected together, and the connectedhollow structure has a cylindrical or gutter-like overall shape. Thethirty-first embodiment is suitable for use as a frame structure forpackaging bottles or like articles having a rod-shaped drum portion.

The thirty-second embodiment of the present invention is a modificationof the connected hollow structure of the twenty-ninth embodiment whereinthe longitudinal surfaces of the first and second hollow structures arerespectively connected together, and the connected hollow structure hasa rising portion formed at least on one surface to gradually rise fromone portion to the other. The connected hollow structure of thethirty-second embodiment is suitable for use as a member for packagingan article by forming the rising portion on one surface so as to fit theexternal shape of the article.

The thirty-third embodiment of the present invention modifies theconnected hollow structure of the thirty-second embodiment to have apitch of the first and second hollow structures formed in the risingportion smaller in proportion to the scale of rising. Since the pitch ofthe hollow structures formed in the rising portion is small, thewithstanding strength against a planar force applied to the risingportion is equal to that against the planar force applied to a portionother than the rising portion.

The thirty-fourth embodiment of the present invention, which may be amodification of the connected hollow structure of any of the nineteenthto thirty-third embodiments, adjacent side walls common to the first andsecond hollow structures have an appropriate number of bending nodestripes extending parallel to the length of the hollow structures. Whena force of not less than a predetermined value is applied perpendicularto the hollow structures of the connected hollow structure in thisthirty-fourth embodiment, the side walls common to adjacent first andsecond hollow structures are bent along the nodes to a certain extentand function as cushions to absorb such a force.

The thirty-fifth embodiment of the present invention is a modificationof the connected hollow structure of the thirty-fourth embodimentwherein each bending node takes the shape of a small groove and isformed on one surface of each side wall common to adjacent first andsecond hollow structures, and the grooves are bent inwardly in a convexshape when the side walls are bent.

The thirty-sixth embodiment of the present invention may be amodification of the connected hollow structure of any of the nineteenthto thirty-third embodiments. In this embodiment at least part of thefirst and second hollow structures have an appropriate number of holesformed in sides which do not appear at the surfaces of the connectedstructure. Thus, the weight of the connected hollow structure is reducedin proportion to the number of holes, and the side walls of the hollowstructures having the holes easily adsorb a planar force, and as aresult, show more flexible elasticity.

The thirty-seventh embodiment of the present invention is a modificationof the connected hollow structure of the third embodiment wherein thefirst and second hollow structures are formed so as to gradually reducein sectional size from one end toward the other. The thirty-seventhembodiment has a circular or sectorial plane such that the side of eachhollow structure having the smaller sectional size forms an innerperiphery, and both surfaces of the connected hollow structure areinclined downwards toward the inner periphery. Thus, the connectedhollow structure in the thirty-seventh embodiment is suitable for use asa packaging member for protecting the end of a rod-shaped member bybringing the connected hollow structure into contact with the end of therod-shaped member.

The thirty-eighth embodiment of the present invention is a modificationof the connected hollow structure of the third embodiment wherein all orpart of at least either the first or second hollow structures have aplurality of small hollow portions. Since the hollow structures have theplurality of small hollow portions, the withstanding strength against aplanar force is increased. Thus, the connected hollow structure in thethirty-eighth embodiment is suitable for use as a carrier for carryingadsorbents by utilizing the small hollow portions of the hollowstructures.

In a thirty-ninth embodiment of the present invention, which is amodification of the connected hollow structure of the third embodiment,the first and second hollow structures have a pentagonal or morepolygonal section, and either the first or second hollow structures havea portion of a concave section formed in the side wall common toadjacent first and second hollow structures adjacent to each other. Whena planar load is applied to the connected hollow structure of thethirty-ninth embodiment, the side walls are further bent along theconcave portions so as to enlarge the concave portions, andsatisfactorily function as cushions to absorb such a planar load.

The fortieth embodiment of the present invention is a modification ofthe connected hollow structure of the first embodiment wherein parallelconnecting sheet portions are bonded together, and a large number ofcylindrical hollow structures are formed by bonding lengthwise jointportions between adjacent connecting sheet portions. The fortiethembodiment is suitable for use as a packaging member for protectinglinear fluorescent lamps or like rod-shaped or cylindrical articles tobe packaged by inserting such articles into the cylindrical hollowstructures, or as other packaging members such as a cushioning materialby making use of flexible cushioning properties of the hollowstructures.

The forty-first embodiment of the present invention is a modification ofthe connected hollow structure of the fortieth embodiment wherein thehollow structures have a circular or elliptical section. Therefore, theforty-first embodiment is more suitable for use as a packaging memberfor protecting rod-shaped or cylindrical articles to be packaged byinserting such articles into the hollow structures, or as otherpackaging members such as a cushioning material by making use of thecushioning properties of the hollow structures.

The forty-second embodiment of the present invention is a modificationof the connected hollow structure of the fortieth or forty-firstembodiment wherein the connected hollow structure has a cylindricalshape with the hollow structures positioned along the inner periphery.The connected hollow structure in the forty-second embodiment issuitable for use as a cushioning material for articles to be packaged,or as other packaging members for protecting bottles or like articleshaving a drum portion by inserting such articles into the connectedhollow structure.

The forty-third embodiment of the present invention is a modification ofthe connected hollow structure of the first embodiment wherein a largenumber of first and second hollow structures having a drop-shaped orpseudo drop-shaped section are formed in an alternate arrangement and inan alternately inverse position by forming portions having the sectionalshape of a letter S and portions having the sectional shape of aninverted letter S in an alternate arrangement such that the side of eachportion having the shape of the letter S is connected to the side of theadjacent portion having the shape of the inverted letter S. Theconnected hollow structure of the forty-third embodiment is suitable foruse as a packaging member for protecting rod-shaped or cylindricalarticles to be packaged by inserting such articles into the hollowstructures, or as other packaging members such as a cushioning materialby making use of the cushioning properties of the hollow structures.

In the forty-fourth embodiment of the present invention either the firstor second hollow structures are smaller in sectional size than theothers, and the connected hollow structure has an overall cylindricalshape with the hollow structures of the smaller sectional sizepositioned along the inner periphery. The connected hollow structure ofthe forty-fourth embodiment is suitable for use as a cushioning materialfor articles to be packaged, or as other packaging members forprotecting bottles or like articles having a drum portion by insertingsuch articles into the connected hollow structure.

The forty-fifth embodiment of the present invention is a modification ofthe connected hollow structure of the first embodiment wherein a largenumber of hollow structures are formed in a dense arrangement inparallel to each other such that first hollow portions having an angularsection and second hollow portions having an inverted angular sectionare combined together in a symmetrical shape, and the hollow structuresadjacent to each other are connected together substantially in the shapeof a letter S or an inverted letter S. Since the hollow structurescomposed of the hollow portions show flexible elasticity, the connectedhollow structure of the forty-fifth embodiment is suitable for use as apackaging member such as a cushioning material for articles to bepackaged, and as other packaging members for protecting linearfluorescent lamps or like rod-shaped or cylindrical articles to bepackaged by inserting such articles into the hollow portions. Further,when the connected hollow structure of the forty-fifth embodiment hasmore hollow structures which are rounded in a cylindrical shape on thewhole, the hollow portions positioned along the cylindrical innersurface are compressively transformed to easily form a connected hollowstructure of a cylindrical shape. Thus, the connected hollow structureof the forty-fifth embodiment is suitable for use as a packaging memberfor protecting bottles or like articles.

The forty-sixth embodiment of the present invention is a modification ofthe connected hollow structure of the forty-fifth embodiment whereineither the first or second hollow portions have a semicircular,trapezoidal or triangular section, and the others have a semicircular,trapezoidal or triangular section in inverse relation to theaforementioned hollow portions. The connected hollow structure in theforty-sixth embodiment has an advantage in being easily fabricated,since the hollow portions have the shape as described above.

The forty-seventh embodiment of the present invention is wholly orpartly formed of the connected hollow structure of any of the first toforty-sixth embodiments. The packaging member of the forty-eighthembodiment of the present invention is composed of a connected bottomstructure, a connected side structure placed uprightly on the side ofthe connected bottom structure, and a connected rear structure placeduprightly on the rear of the connected bottom structure and at a rightangle with the connected side structure. The connected bottom structure,the connected side structure and the connected rear structure arerespectively formed of the connected hollow structure. The packagingmember of the forty-eighth embodiment is suitable for use as a cornerprotection frame for protecting an article having a corner includingthree sides at right angles to one another by bringing the cornerportion of such an article into contact with the inside of the packagingmember.

The forty-ninth embodiment of the present invention is a modification ofthe packaging member of the forty-eighth embodiment wherein theconnected side structure is placed on the connected bottom structuresuch that first and second hollow structures of the connected sidestructure are substantially at right angles with first and second hollowstructures of the connected bottom structure; the connected rearstructure is placed on the connected bottom structure such that firstand second hollow structures of the connected rear structure extendalong the first and second hollow structures of the connected bottomstructure, while being oriented at an angle of 90° with the first andsecond hollow structures of the connected bottom structure; theconnected side structure and the connected rear structure are connectedto the connected bottom structure through individual connecting sheetportions; and the connected bottom structure, the connected sidestructure and the connected rear structure respectively have the firstand second hollow structures of the same sectional shape and arecomprised of a piece of sheet. Since the packaging member of theforty-ninth embodiment is formed as described above, the connectedbottom structure, the connected side structure and the connected rearstructure are substantially uniform in withstanding strength andelasticity. Further, this packaging member is comprised of a piece ofsheet, and as a result, is formed economically.

The fiftieth embodiment of the present invention is a modification ofthe packaging member in the forty-eighth or forty-ninth embodimentwherein the surfaces which face the inside of the packaging member, ofat least part of hollow structures have a circular arc section. Thus,when a planar force is applied to the connected hollow structure, theinside facing surfaces of the circular arc section show elasticity(cushioning properties) and partially absorb such a planar force.

The fifty-first embodiment of the present invention is a modification ofthe layered connected hollow structure of the nineteenth embodimentformed in block shape such that hollow portions of each layer are inparallel with each other. The packaging member of the fifty-firstembodiment is suitable for use as a packaging support block orcushioning block, and as a packaging frame structure for encasingbottles or like articles by inserting such articles into the hollowstructures.

The fifty-second embodiment of the present invention is a modificationof the packaging member of the fifty-first embodiment, wherein a hole isformed perpendicularly to the hollow structures of the connected hollowstructure. The packaging member of the fifty-second embodiment issuitable for use as a packaging frame structure and also serves as acushioning material for packaging an article having a portion fit to theshape of the hole by inserting such a portion of the article into thehole.

The fifty-third embodiment of the present invention is a modification ofthe fifty-first or fifty-second embodiment wherein the first and secondhollow structures of the connected hollow structures of the layers areformed in parallel with each other in a symmetrical arrangement insection, and the connected hollow structures of the layers adjacent toeach other are connected together as one body and comprised of a singlesheet. In the packaging member of the fifty-third embodiment each layershows substantially uniform elasticity and withstanding strength againsta planar force. Further, the packaging member of the fifty-thirdembodiment is wholly comprised of a single sheet, and as a result, isformed economically.

The fifty-fourth embodiment of the present invention is composed of aconnected bottom structure, a pair of connected side structures placeduprightly on both sides of the connected bottom structure, a connectedfront structure placed uprightly on the front of the connected bottomstructure and at right angles with the connected side structures, and aconnected rear structure placed uprightly on the rear of the connectedbottom structure and at right angles with the connected side structures,and the connected bottom structure. The connected side structures, theconnected front structure and the connected rear structure are formed ofthe connected hollow structure. The packaging member of the fifty-fourthembodiment takes the overall shape of a relatively high-edged tray, andtherefore is suitable for use as a protecting frame for packaging anarticle having a portion fit for the internal shape of the packagingmember by inserting such a portion of the article into the packagingmember, or as a pallet for carrying articles and so on.

The fifty-fifth embodiment of the present invention is a modification ofthe packaging member of the fifty-fourth embodiment wherein theconnected front structure and the connected rear structure are placed onthe connected bottom structure such that the first and second hollowstructures of the connected front structure and the connected rearstructure extend along the first and second hollow structures of theconnected bottom structure, while being oriented at an angle of 90° withthe first and second hollow structures of the connected bottomstructure. Both the connected side structures are placed on theconnected bottom structure such that the first and second hollowstructures of the connected side structures are substantially at rightangles with the first and second hollow structures of the connectedbottom structure. The connected front structure and the connected rearstructure are connected to the connected bottom structure throughconnecting sheet portions. The connected front structure and oneconnected side structure, and the connected rear structure and the otherconnected side structure are respectively connected together throughindividual connecting sheet portions. The connected bottom structure,both the connected side structures, the connected front structure andthe connected rear structure have the first and second hollow structuresof the same sectional shape and are comprised of a single sheet.

In the fifty-fifth embodiment, the connected bottom structure, both theconnected side structures, the connected front structure and theconnected rear structure show substantially uniform withstandingstrength and elasticity. Further, the packaging member in thefifty-fifth embodiment is wholly comprised of a single sheet, and as aresult, is formed economically.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary perspective view of a connected hollow structurein a first embodiment according to the present invention;

FIG. 2 is a fragmentary end view of the connected hollow structure ofFIG. 1, which is transformed under the action of a vertical load;

FIG. 3 is a fragmentary the connected hollow structure developed planview of FIG. 1;

FIG. 4 is a fragmentary perspective view of a connected hollow accordingto the present invention;

FIG. 5 is a fragmentary developed plan view of the connected hollowstructure of FIG. 4;

FIG. 6 is a fragmentary enlarged sectional view of the connected hollowstructure of FIG. 4;

FIG. 7 is a fragmentary perspective view of a connected hollow structurein a third embodiment according to the present invention;

FIG. 8 is a perspective view of a connected hollow structure in a fourthembodiment according to the present invention;

FIG. 9 is an end view of the connected hollow structure of FIG. 8, whichis transformed under the action of a vertical load;

FIG. 10 is a perspective view of a connected hollow structure in a fifthembodiment according to the present invention;

FIG. 11 is a fragmentary developed plan view of the connected hollowstructure of FIG. 10;

FIG. 12 is a developed perspective view of the connected hollowstructure of FIG. 10 immediately before completion;

FIG. 13 is a perspective view of a connected hollow structure in a sixthembodiment according to the present invention;

FIG. 14 is a perspective view of a connected hollow structure in aseventh embodiment according to the present invention;

FIG. 15 is a fragmentary developed plan view of the connected hollowstructure of FIG. 13;

FIG. 16 is a developed side view of the connected hollow structure ofFIG. 13 immediately before completion;

FIG. 17 is a fragmentary developed plan view of the connected hollowstructure of FIG. 14;

FIG. 18 is a perspective view of a connected hollow structure in aneighth embodiment according to the present invention;

FIG. 19 is a fragmentary developed plan view of the connected hollowstructure of FIG. 18;

FIG. 20 is a perspective view of a connected hollow structure in a ninthembodiment according to the present invention;

FIG. 21(A) is an end view of a connected hollow structure in a tenthembodiment according to the present invention;

FIG. 21(B) is an end view of a connected hollow structure in an eleventhembodiment according to the present invention;

FIG. 22 is a developed plan view of the connected hollow structure ofFIG. 20;

FIG. 23 is a developed side view of a connected hollow structure in atwelfth embodiment according to the present invention before completedevelopment;

FIG. 24 is a side view of the connected hollow structure of FIG. 23after completion;

FIG. 25 is a fragmentary side view of a connected hollow structure in athirteenth embodiment according to the present invention;

FIG. 26 is a fragmentary side view of a connected hollow structure in afourteenth embodiment according to the present invention;

FIG. 27 is a perspective view of a connected hollow structure in afifteenth embodiment of the present invention;

FIG. 28 is a perspective view of a connected hollow structure in asixteenth embodiment of the present invention;

FIG. 29 is a perspective view of a connected hollow structure in aseventeenth embodiment according present invention;

FIG. 30 is a fragmentary end view of a connected hollow structure in aneighteenth embodiment according present invention;

FIG. 31 is a fragmentary end view of a connected hollow structure in anineteenth embodiment according to the present invention;

FIG. 32 is a fragmentary end view of a connected hollow structure in atwentieth embodiment according to the present invention;

FIG. 33 is a fragmentary end view of a connected hollow structure in atwenty-first embodiment according to the present invention;

FIG. 34 is a fragmentary end view of a connected hollow structure in atwenty-second embodiment according to the present invention;

FIG. 35 is a fragmentary end view of a connected hollow structure in atwenty-third embodiment according to the present invention;

FIG. 36 is a fragmentary perspective view of a connected hollowstructure in a twenty-fourth embodiment according to the presentinvention;

FIG. 37 is a fragmentary end view of a connected hollow structure in atwenty-fifth embodiment according to the present invention;

FIG. 38 is a fragmentary end view of a connected hollow structure in atwenty-sixth embodiment according to the present invention;

FIG. 39 is a fragmentary end view of a connected hollow structure in atwenty-seventh embodiment according to the present invention;

FIG. 40 is a fragmentary end view of a connected hollow structure in atwenty-eighth embodiment according to the present invention;

FIG. 41 is a fragmentary perspective view of a connected hollowstructure in a twenty-ninth embodiment according to the presentinvention;

FIG. 42(C) is a fragmentary end view of a connected hollow structure ina thirtieth embodiment according to the present invention;

FIG. 42(D) is a fragmentary end view of a connected hollow structure ina thirty-first embodiment according to the present invention;

FIG. 43 is an end view of a connected hollow structure in athirty-second embodiment according to the present invention;

FIG. 44 is an end view of a connected hollow structure in a thirty-thirdembodiment according to the present invention;

FIG. 45 is a fragmentary perspective view of a connected hollowstructure in a thirty-fourth embodiment according to the presentinvention;

FIG. 46 is a fragmentary end view of a connected hollow structure in athirty-fifth embodiment according to the present invention;

FIG. 47 is a fragmentary end view of a connected hollow structure in athirty-sixth embodiment according to the present invention;

FIG. 48 is a fragmentary perspective view of a connected hollowstructure in a thirty-seventh embodiment according to the presentinvention;

FIG. 49 is a fragmentary perspective view of a connected hollowstructure in a thirty-eighth embodiment according to the presentinvention;

FIG. 50 is a fragmentary perspective view of a connected hollowstructure in a thirty-ninth embodiment according to the presentinvention;

FIG. 51 is a fragmentary perspective view of a connected hollowstructure in a fortieth embodiment according to the present invention;

FIG. 52 is a fragmentary perspective view of a connected hollowstructure in a forty-first embodiment according to the presentinvention;

FIG. 53 is a perspective view of a connected hollow structure in aforty-second embodiment according to the present invention;

FIG. 54 is an end view of the connected hollow structure of FIG. 53,which is transformed under the action of a vertical load;

FIG. 55 is a fragmentary end view of a connected hollow structure in aforty-third embodiment according to the present invention;

FIG. 56 is a fragmentary perspective view of a connected hollowstructure in a forty-fourth embodiment according to the presentinvention;

FIG. 57 is a fragmentary end view of a connected hollow structure in aforty-fifth embodiment according to the present invention;

FIG. 58 is a fragmentary end view of a connected hollow structure in aforty-sixth embodiment according present invention;

FIG. 59 is a fragmentary end view of a connected hollow structure in aforty-seventh embodiment according present invention;

FIG. 60 is a fragmentary end view of a connected hollow structure in aforty-eighth embodiment according present invention;

FIG. 61 is a fragmentary end view of a connected hollow structure in aforty-ninth embodiment according present invention;

FIG. 62 is a fragmentary perspective view of a connected hollowstructure in a fiftieth embodiment according to the present invention;

FIG. 63 is a fragmentary end view of a connected hollow structure in afifty-first embodiment according present invention;

FIG. 64 is a perspective view of a connected hollow structure in afifty-second embodiment according present invention;

FIG. 65 is a fragmentary end view of a connected hollow structure in afifty-third embodiment according present invention;

FIG. 66 is a fragmentary side view of a connected hollow structure in afifty-fourth embodiment according present invention;

FIG. 67 is a fragmentary side view of a connected structure in afifty-fifth embodiment according to the present invention;

FIG. 68 is a fragmentary perspective view of a connected hollowstructure in a fifty-sixth embodiment according to the presentinvention;

FIG. 69 is a fragmentary side view of a connected hollow structure in afifty-seventh embodiment according to the present invention;

FIG. 70 is a fragmentary perspective view of a connected hollowstructure in a fifty-eighth embodiment according to the presentinvention;

FIG. 71 is a side view of a connected hollow structure in a fifty-ninthembodiment according to the present invention;

FIG. 72 is a fragmentary perspective view of a connected hollowstructure in a sixtieth embodiment according to the present invention;

FIG. 73 is a fragmentary perspective view of a connected hollowstructure in a sixty-first embodiment according to the presentinvention; and

FIG. 74 is a fragmentary perspective view of a connected hollowstructure in a sixty-second embodiment according to the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter will be described connected hollow structures according tothe preferred embodiments of the present invention in detail withreference to the accompanying drawings.

(First embodiment)

FIG. 1 shows that the connected hollow structure 1 in a first embodimentis fabricated from a sheet a (See FIG. 2) consisting of a piece ofboard. The connected hollow structure 1 comprises hollow structuresincluding first hollow structures 11, which are of the substantiallysame size and have an isosceles triangular section (close to a regulartriangular section in this embodiment), and second hollow structures 12which are substantially equal in size and sectional shape to the firsthollow structures. However, the second hollow structure 12 at both endsof the connected hollow structure 1 has a right-angled triangularsection, and is equal in height to other second hollow structures 12.

The first and second hollow structures 11, 12 are formed such that acorner portion (i.e., an angular portion included in two equilaterals)13 of each first hollow structure 11 and that of each second hollowstructure 12 are directed to be reverse to each other, and a partialcircumference 14 forming one side surface (i.e., a base surface) of eachfirst hollow structure 11 and that forming one side surface of eachsecond hollow structure 12 face the opposite surfaces of the connectedhollow structure 1.

The first hollow structures 11, 11 adjacent to each other are bondedtogether in a portion of the corner portion 13 of each second hollowstructure 12 positioned between the first hollow structures 11, 11adjacent to each other. The second hollow structures 12, 12 adjacent toeach other are bonded together in a portion of the corner portion 13 ofeach first hollow structure 11 positioned between the second hollowstructures 12, 12 adjacent to each other.

The first and second hollow structures 11, 12 adjacent to each otherhave common side walls 15, which form the borders between the first andsecond hollow structures adjacent to each other. Therefore, each sidewall 15 in the border between the first and second hollow structuresadjacent to each other has the same thickness as the sheet a which isused as the material of the connected hollow structure.

According to the connected hollow structure 1 formed as described above,the partial circumferences 14 of the first hollow structures 11 adjacentto each other and those of the second hollow structures 12 adjacent toeach other are respectively connected together. Thus, the connectedhollow structure 1 has a panel-like shape substantially uniform inapparent thickness T, and takes the shape resembling a unicursal figurein section.

The connected hollow structure 1 in the first embodiment is fabricatedas follows. Firstly, as shown in FIG. 3, while the sheet a used as thematerial of the connected hollow structure is being delivered, convexfolds a2, a2, along which the sheet a is folded in a convex shape (i.e.,the shape of an inverted letter V in section), and concave folds a1, a1,along which the sheet a is folded in a concave shape (i.e., the shape ofa letter V), are formed on the sheet a so as to extend in the traversedirection of the sheet in an alternate arrangement every two rows and inparallel to each other by using, for instance, a press or rotary presscutter. When a corrugated fiberboard is applied to the sheet a, thefolds a1, a2 are formed so as to intersect flutes (not shown) of thecorrugated fiberboard at a predetermined angle.

The distance between the concave folds a1, a1, that between the convexfolds a2, a2 and that between the concave and convex folds a1, a2adjacent to each other are determined according to the sectional size ofthe hollow structures 11, 12.

Subsequently, the top surface of the sheet a at portions of the convexfolds a2 and the undersurface of the sheet a at portions of the concavefolds a1 are respectively coated with glue (i.e., an adhesive).Thereafter, the sheet a is folded in sequence along the folds a1, a2from the leading end of the sheet a in the delivery direction to formthe upper and lower partial circumferences 14, 14, and the sides of theupper and lower partial circumferences 14, 14 adjacent to each other arebonded together so as to be flush with each other.

When the sheet a is folded in sequence as described above, the convexfolds a2, a2 form upward corner portions 13 of the first hollowstructures 11, and the concave folds a1, a1 form downward cornerportions 13 of the second hollow structures 12. Thus, it is possible toform the connected hollow structure 1 as shown in FIG. 1 by bonding bothsides of the partial circumferences 14, 14 of the mutually-adjacentfirst hollow structures 11, 11 together, while bonding both sides of thepartial circumferences 14, 14 of the mutually-adjacent second hollowstructures 12, 12 together, and by cutting the sheet a, which is beingdelivered, along a required portion.

The connected hollow structure 1 in the first embodiment shows highwithstanding strength, which also acts uniformly on the whole, since thehollow structures 11, 12 have the isosceles triangular section, and aplanar force is applied to the connected hollow structure 1 so as tosubstantially uniformly act on the uniformly-inclined side walls commonto the adjacent hollow structures 11, 12.

When the connected hollow structure receives a planar force of not lessthan a predetermined value, the hollow structures 11, 12 adjacent toeach other are transformed such that the inclined side walls thereof arebent as shown in FIG. 2, and as a result, the connected hollow structure1 shows elasticity (i.e., cushioning properties) within the limit ofthis transformation.

Thus, the connected hollow structure 1 in this embodiment is used as apanel-shaped packaging member or a cushioning material, and as a corematerial of a heat-insulating panel or like panels, a wall material, apallet, and a carrier for carrying adsorbents.

Otherwise, the connected hollow structure 1 in this embodiment is usedas a packaging frame structure for wholly packaging bottles, fluorescenttubes, electronic parts or like articles by inserting such articles intohollow portions of the hollow structures 11, 12.

An A-flute corrugated fiberboard (having a flute height of 5.5 mm)consisting of a kraft linerboard of 160 g/m² and a corrugating medium of125 g/m² was fabricated as well as a connected hollow structure, whichhas a sectional shape similar to that of the connected hollow structure1 in this embodiment and shows withstanding strength against a planarforce substantially similar to that of the A-flute corrugatedfiberboard. In this case, the latter was about one-seventh to one-tenthas heavy as the former.

Thus, the connected hollow structure 1 of the sectional shape like thefirst embodiment is extremely higher in withstanding strength against aplanar force and also far smaller in apparent specific gravity (g/cc)than the corrugated fiberboard.

Further, the connected hollow structure 1 shows high withstandingstrength against an external force applied in the direction of thehollow structures 11, 12, since the hollow structures 11, 12 areconnected together in a parallel and dense arrangement.

The strength of elastic force of the connected hollow structure 1 variesdepending on the quality and thickness of the sheet a, and the shape andsize of the hollow structures 11, 12. When the hollow structures 11, 12have the isosceles triangular section like the first embodiment, theelasticity is made more flexible, whereas the elastic force orwithstanding strength is reduced accordingly as the bases of the hollowstructures 11, 12 in section are enlarged.

It is possible to form the connected hollow structure 1, which has thevoid content according to the purpose and shows the hardness,withstanding strength and elastic force (cushioning force) according tothe purpose, by freely selecting the sectional size of the hollowstructures 11, 12.

Since the connected hollow structure 1 is not formed as a standardizedproduct (different from the case of corrugated fiberboard), it ispossible to select the material or the sectional shape of the hollowstructures 11, 12 according to the purpose.

Further, the connected hollow structure 1 takes the shape resembling aunicursal figure in section, and therefore, is fabricated from a singlesheet. Thus, bonding a plurality of sheets of various sectional shapestogether in layers is not needed (also different from the case offabricating the corrugated fiberboard) and, as a result, it is possibleto fabricate the connected hollow structure 1 through fewer steps at lowcost.

(Second embodiment)

FIG. 4 is a perspective view showing a connected hollow structure 1 of asecond embodiment according to the present invention which issubstantially similar in basic constitution to the connected hollowstructure in the first embodiment.

Dovetailed projections 16 of a width narrowing toward their bases areformed at certain intervals on both surfaces of the connected hollowstructure 1 so as to horizontally project from one side of the partialcircumferences 14 of the first hollow structures 11, 11 adjacent to eachother and also from one side of the partial circumferences 14 of thesecond hollow structures 12, 12 adjacent to each other. On the otherhand, recess holes 17 fitted to the projections 16 are formed on theother side of the partial circumferences 14. Thus, the first hollowstructures 11, 11 adjacent to each other and the second hollowstructures 12, 12 adjacent to each other are respectively connectedtogether by fitting the projections 16 into the corresponding recessholes 17.

In order to respectively connect the first hollow structures 11, 11 andthe second hollow structures 12, 12 together, the projections 16 areformed by incising the side walls adjacent to the partial circumferences14 so as to start incising from portions of the folds a1, a2 in case offorming the folds a1, a2 on the sheet a. No folds a1, a1 are formedalong the bases of the projections 16.

At the same time, the recess holes 17 fitted to the projections 16 areformed in portions of the side walls 15, 15 such that the recess holes17 extend over the partial circumference 14 adjacent to each side wallup to an extent corresponding to the thickness of the sheet a.

The projections 16 enter the recess holes 17 so as to cover the recessholes with the projections, as shown on an enlarged scale in FIG. 6, byforming the projections 16 and the recess holes 17 in required portionsof the sheet a as described above. Thus, the projections 16 are smoothlyfitted into the recess holes 17, in case of folding the sheet a alongthe folds a1, a2.

The connected hollow structure 1 in the second embodiment is fabricatedmore simply, since no step of gluing the sheet a is needed in case ofrespectively connecting the partial circumferences 14, 14 of themutually-adjacent first hollow structures 11, 11 and those of themutually-adjacent second hollow structures 12, 12 together.

Other respects of the functions and effects of the connected hollowstructure 1 in the second embodiment are substantially similar to thoseof the connected hollow structure 1 in the first embodiment, and hence,the description thereof will be omitted.

(Third embodiment)

FIG. 7 shows a connected hollow structure 1 of a third embodimentaccording to the present invention wherein a large number of holes 18 ofa predetermined shape are formed in the inclined side walls 15 whichform the borders between the hollow structures 11, 12 adjacent to eachother.

Since the large number of holes 18 are formed in the side walls 15, theconnected hollow structure 1 in this embodiment reduces its overallapparent specific gravity and shows more flexible elasticity (i.e.,reduces its elastic force) accordingly.

Thus, it is possible to form a connected hollow structure, which showsdesired elasticity, by selecting the shape, size and density of theholes 18.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the third embodiment are substantiallysimilar to those of the connected hollow structure in the firstembodiment, and hence, the description thereof will be omitted.

(Fourth embodiment)

FIG. 8 shows a connected hollow structure 1 of a fourth embodiment whichhas a flat panel-like overall shape similar to the connected hollowstructure 1 in the first embodiment, except that first and second hollowstructures 11, 12 in the fourth embodiment have a rectangularequilateral triangular section.

The connected hollow structure 1 in this embodiment is fabricated asfollows. Firstly, a sheet (not shown) used as a material of theconnected hollow structure 1 is folded along concave and convex folds.In this case, the folding of the sheet starts according to the directionas shown by an arrow b in FIG. 8. Subsequently, while the sheet is beingfolded in sequence, the partial circumferences 14 adjacent to each otherare connected together by bonding in portions of upper and lower cornerportions 13 such that the hollow structures 11, 12 of the rectangularequilateral triangular section are densely arranged in an alternatelyinverse position in section.

The connected hollow structure 1 in this embodiment withstands a planarforce mainly by vertical side walls and inclined side walls 15 of thehollow structures 11, 12. Thus, when the connected hollow structure 1 isexposed to a planar force of not less than a predetermined value, theside walls 15 are bent as shown in FIG. 9 and absorb such a planarforce.

Other respects of the constitution, functions and effects of theconnected hollow structure in the fourth embodiment are substantiallysimilar to those of the connected hollow structure in the firstembodiment, and hence, the description thereof will be omitted.

(Fifth embodiment)

FIG. 10 shows a packaging member comprised of a connected hollowstructure 1 of a fifth embodiment which is formed as a corner protectionframe, which also serves as a cushioning material for protecting acorner portion of an article when packaged, and is composed of aconnected bottom structure 1 a, a connected side structure 1 b uprightlyplaced on the top surface of one side of the connected bottom structure1 a, and a connected rear structure 1 c uprightly and sideways placed onthe top surface of the rear side of the connected bottom structure 1 a.The connected bottom, side and rear structures 1 a, 1 b, 1 c aresubstantially at right angles with one another.

First and second hollow structures 11, 12 of the connected bottom, sideand rear structures 1 a, 1 b, 1 c are of the same size and have anisosceles triangular section. However, the second hollow structures 12on both ends of the connected bottom, side and rear structures 1 a, 1 b,1 c have a right-angled triangular section.

The connected bottom structure 1 a and the connected side structure 1 bare connected together as one body through connecting sheet portions a3,and the connected bottom structure 1 a and the connected rear structure1 c are connected together as one body through another connecting sheetportion a4.

The connected hollow structure 1 in the fifth embodiment is fabricatedas follows. Firstly, as shown in FIG. 11, while a sheet a is beingdelivered in a certain direction convex folds a2, a2 and concave foldsa1, a1 are formed on the sheet a so as to extend in the cross directionof the sheet in an alternate arrangement according to the sectionalheight and base width of the hollow structures 11, 12, similarly to thecase in the first embodiment.

Recess portions a7 of a width corresponding to the sectional height ofthe hollow structures 11, 12 are formed along the border between a sheetportion 1 a′ which forms the connected bottom structure 1 a shown inFIG. 10, and a sheet portion 1 b′, which forms the connected sidestructure 1 b, by cutting portions other than the connecting sheetportions a3 formed in alignment with portions defined by the adjacentfolds a1, a1. A fold a5 is formed on one required end of each connectingsheet portion a3 so as to extend at right angles with the folds a1, a1.

Parallel folds a6, a6 are formed along the border between the sheetportion 1 a′, which forms the connected bottom structure 1 a shown inFIG. 10, and a sheet portion 1 c′, which forms the connected rearstructure 1 c, such that the folds a6, a6 are positioned on both sidesof the connecting sheet portion a4. Further, a recess portion a8 of awidth corresponding to the sectional height of the hollow structures 11,12 is formed from a portion of either fold a6 so as to extend over aportion corresponding to the length of the connected rear structure 1 c.

The required surface of the sheet a is coated with glue (i.e., anadhesive) along the folds a1, a2 and a6.

Subsequently, while the sheet a is being folded in sequence along thefolds a1, a2 and a6 to form the first and second hollow structures 11,12, the edges of the first hollow structures 11 adjacent to each otherand those of the second hollow structures 12 adjacent to each other arebonded together, and the sheet a is cut along a desired portion.However, when a sheet previously cut in a predetermined shape is used, acutting step is not needed.

According to the above procedure, a connected hollow structure 1′ in adeveloped state is formed, in which the connected side structure 1 b isconnected to one end of the connected bottom structure 1 a through theconnecting sheet portions a3, and the connected rear structure 1 c isconnected to the side of the connected bottom structure 1 a through theconnecting sheet portion a4, as shown in FIG. 12.

The connected hollow structure 1′ in the developed state shown in FIG.12 is used in distribution as it is. However, when it is necessary topackage articles in a connected hollow structure immediately after thefabrication, the connected hollow structure 1 is formed as shown in FIG.1 by raising the connected side structure 1 b and the connected rearstructure 1 c together with the respective connecting sheet portions a3,a4 in the direction shown by arrows in FIG. 12.

For instance, in a case where there is a possibility that the connectedhollow structure 1 in the state shown in FIG. 10 is collapsed whenpacked, the connected side structure 1 b and the connected rearstructure 1 c may be fixed to the connected bottom structure 1 a bybonding or other appropriate means, as needed.

In addition to the procedure of fabrication as described above, theconnected hollow structure 1 may be fabricated by independently formingthe connected bottom structure 1 a, the connected side structure 1 b andthe connected rear structure 1 c, then combining these structures withone another as shown in FIG. 10, and consequently connecting or fixingthe combined structures together.

The connected hollow structure in the fifth embodiment is comprised of asingle sheet as described above, and therefore, may be fabricatedthrough fewer steps at lower cost.

Since each of the hollow structures 11, 12 as the components of theconnected hollow structure has the isosceles triangular section having asectional height larger than a base, the connected bottom, side and rearstructures 1 a, 1 b, 1 c show high withstanding strength against aplanar force.

Further, since the connected bottom, side and rear structures 1 a, 1 b,1 c are comprised of the same sheet a, and the hollow structures 11, 12included in these structures have the same shape and are of the samesize, the connected bottom, side and rear structures 1 a, 1 b, 1 c showsubstantially uniform withstanding strength against a planar force.

Other respects of the constitution, functions and effects of theconnected hollow structure in the fifth embodiment are substantiallysimilar to those of the connected hollow structure in the firstembodiment, and hence, the description thereof will be omitted.

(Sixth embodiment)

FIG. 13 shows a packaging member formed of a connected hollow structure1 of a sixth embodiment which is formed as a support block forsupporting articles when packaged, and is composed of connectedstructures 1 d, 1 e, 1 f, 1 g, 1 h of the same structure and of the samesize, which are formed in layers such that hollow structures 11, 12 (ofa regular triangular section) of these connected structures extend inparallel to each other and are arranged in a symmetrical shape.

The connected hollow structure 1 in the sixth embodiment is fabricatedas follows. Firstly, as shown in FIG. 15, while a sheet a is beingdelivered in a certain direction, convex folds a2, a2 and concave foldsa1, a1 are formed on the sheet a so as to extend in the transversedirection of the sheet in an alternate arrangement according to thesectional height and base width of the hollow structures 11, 12,similarly to the case in the first embodiment.

Folds a9 are formed between the convex folds a2, a2 along the borderbetween sheet portions 1 d′, 1 e′ , which respectively form thestructures 1 d, 1 e of FIG. 13, and the border between sheet portions 1f′, 1 g′ which respectively form the structures 1 f, 1 g. Further,breaks a10 are formed along these borders other than portions of thefolds a9 so as to be alignment with the folds a9.

On the other hand, folds a9 are formed between the concave folds a1, a1along the border between sheet portions 1 e′ , 1 f′, which respectivelyform the structures 1 e, 1 f, and the border between sheet portions 1g′, 1 h′, which respectively form the structures 1 g, 1 h. Further,breaks a10 are formed along these borders other than portions of thefolds a9 so as to be alignment with the folds a9.

The required surface of the sheet a is coated with glue (i.e., anadhesive) along the folds a1, a2.

Subsequently, while the sheet a is being folded in sequence along thefolds a1, a2 to form the hollow structures 11, 12, the edges of thehollow structures 11 adjacent to each other and those of the hollowstructures 12 adjacent to each other are respectively bonded together,and the sheet a is cut as required.

According to the above procedure, a connected hollow structure 1′ isformed, in which the structures 1 d to 1 h are in a developed state, asshown in FIG. 16.

The connected hollow structure 1′ in the developed state as shown inFIG. 16 is used for distribution as it is. However, when it is necessaryto package articles in a connected hollow structure immediately afterthe fabrication, a layered connected hollow structure 1 of a block shapeis formed as shown in FIG. 13 by alternately making a completeface-about of the structures 1 d to 1 g under the hinge action ofportions of the folds a9.

For instance, in a case where there is a possibility that the connectedhollow structure in the state as shown in FIG. 13 is collapsed whenpacked, the structures 1 d to 1 h may be fixed together by bonding orother appropriate means.

The connected hollow structure 1 in the sixth embodiment is used as thepackaging support block and cushioning block as described above, and asa packaging frame structure for packaging bottles or like articles byinserting such articles into the hollow portions. Further, since a largenumber of hollow portions are arranged densely, the connected hollowstructure in this embodiment is suitable for use as a carrier forcarrying adsorbents.

The connected hollow structure 1 in the sixth embodiment is comprised ofa single sheet as described above, and therefore, may be fabricatedthrough fewer steps at lower cost, and the structures 1 d to 1 h showsubstantially uniform elastic force and withstanding strength against aplanar force.

Since each of the hollow structures 11, 12 as the components of theconnected hollow structure has the isosceles triangular section havingthe sectional height larger than the base, the connected hollowstructure 1 shows high withstanding strength against a planar force.

Further, since the hollow structures 11, 12 are formed densely inparallel to each other, the connected hollow structure 1 shows highwithstanding strength against an external force in the direction of thehollow structures 11, 12. Thus, the connected hollow structure 1 in thisembodiment is also suitable for use as a core material of a hollow panel(not shown) by designing the hollow structures 11, 12 to uniformly havea short length, and then inserting the connected hollow structure 1 intothe hollow panel such that the hollow structures thus designed extend inthe thickness direction of the hollow panel.

As a modification of the sixth embodiment, it is possible to fabricate aconnected hollow structure of a block shape by individually forming thestructures 1 d to 1 h of the respective layers, arranging thesestructures in layers and then bonding the layered structures together.

In this case, when a connected hollow structure of a block shape isfabricated such that the hollow structures 11, 12 extend at right anglesto each other, it is possible to form a layered connected structurewhich shows high withstanding strength against an external force inevery direction.

Other respects of the constitution, functions and effects of theconnected hollow structure in the sixth embodiment are substantiallysimilar to those of the connected hollow structure in the firstembodiment, and hence, the description thereof will be omitted.

(Seventh embodiment)

FIG. 14 shows a packaging member formed of a connected hollow structure1 of a seventh embodiment which is a modification of the connectedhollow structure in the sixth embodiment, and is composed of thestructures 1 d to 1 h which are layered in a block shape by making useof the hinge action of folds a9. A quadrangular hole a11′ is formed inthe center of the layered connected hollow structure at right angleswith the hollow structures 11, 12.

The connected hollow structure 1 in the seventh embodiment is fabricatedas follows. Firstly, as shown in FIG. 17, in a step of forming a sheet aconstituted substantially similarly to that shown in FIG. 17, in a stepof forming a sheet a constituted substantially similarly to that shownin FIG. 15, recess holes all, which form the hole a11′ described above,are formed in required portions in the center of sheet portions 1 e to 1h other than a sheet portion 1 d′ which forms the structure 1 d shown inFIG. 14, and the sheet a is folded according to a procedure similar tothat in case of the sixth embodiment.

The connected hollow structure 1 in the seventh embodiment has the holesa11′ formed as described above, and therefore, is suitable for use as apackaging frame structure, which also serves as a cushioning materialfor an article having a portion fit for the shape of the hole a11 byinserting such a portion of the article into the hole a11.

When a recess hole a22 is formed in the sheet portion 1 d′ of FIG. 17similarly to the recess holes a11 formed in the sheet portions 1 e to 1h, portions of the holes a11 form a through hole extending through aconnected hollow structure 1 of a block shape. The connected hollowstructure 1 having the through hole as described above is used forpackaging an article fit for the shape of the through hole by insertingsuch an article through the connected hollow structure 1.

Other respects of the constitution, functions and effects of theconnected hollow structure in the seventh embodiment are substantiallysimilar to those of the connected hollow structure in the sixthembodiment, and hence, the description thereof will be omitted.

(Eighth embodiment)

FIG. 18 shows a packaging member formed of a connected hollow structure1 of an eighth embodiment which has a generally tray-like shape and iscomposed of a connected bottom structure 1 a, a pair of connected sidestructures 1 b, 1 b uprightly placed on both ends of the connectedbottom structure 1 a, a connected front structure 1 i uprightly placedon the front end of the connected bottom structure 1 a, and a connectedrear structure 1 c uprightly placed on the rear end of the connectedbottom structure 1 a.

The connected bottom structure 1 a is connected to the connected frontstructure 1 i and the connected rear structure 1 c through respectiveconnecting portions a4, and the connected front structure 1 i and theconnected rear structure 1 c are connected to the connected sidestructures 1 b, 1 b through respective connecting portions a3.

First and second hollow structures 11, 12 included in the connectedbottom, side, front and rear structures 1 a, 1 b, 1 i, 1 c have aright-angled triangular section having a slightly larger height, and areof the substantially same size.

The connected hollow structure 1 in the eighth embodiment is fabricatedas follows. Firstly, as shown in FIG. 19, while a sheet a of a certainwidth is being delivered in a certain direction, concave folds a1, a1and convex folds a2, a2 are formed on the sheet a so as to extend in thetransverse direction of the sheet in an alternate arrangement accordingto the sectional height and base width of the hollow structures 11, 12.

Recess portions a7 of a width corresponding to the sectional height ofthe hollow structures 11, 12 are formed along the border between a sheetportion 1 c′ which forms the connected rear structure 1 c in FIG. 18,and a sheet portion 1 b′, which forms the connected side structure 1 b,and along the border between a sheet portion 1 i′, which forms theconnected front structure 1 i and the sheet portion 1 b′, by cuttingportions other than connecting sheet portions a3 formed in alignmentwith portions between the folds a1, a1. Further, a fold a5 is formed onone required end of each connecting sheet portion a3 so as to extend atright angles with the folds a1, a1.

Parallel folds a6, a6 are formed along the border between a sheetportion 1 a′, which forms the connected bottom structure 1 a of FIG. 18,and the sheet portion 1 i′ and along the border between the sheetportion 1 a′ and the sheet portion 1 c′ such that the folds a6, a6 arepositioned along both sides of the connecting sheet portion a4. Further,unnecessary portions a12, a12 corresponding to length portions of thestructures 1 b, 1 b are cut from portions aligned with either fold a6 ofthe sheet a.

The required surface of the sheet a is coated with glue (i.e., anadhesive) along the folds a1, a2 and a6.

Subsequently, while the sheet a is being folded in sequence along thefolds a1, a2 and a6 to form the hollow structures 11, 12, the edges ofthe hollow structures 11 adjacent to each other and those of the hollowstructures 12 adjacent to each other are respectively bonded together,and the sheet a is cut along a required portion.

The folding of the sheet a starts according to the direction as shown byan arrow C of FIG. 18, for instance.

According to the above procedure, a connected hollow structure in adeveloped state is formed, in which the connected front and rearstructures 1 i, 1 c are connected to the front and rear portions of theconnected bottom structure 1 a through the connecting sheet portions a4,and the connected side structures 1 b are connected to the sides of theconnected front and rear structures 1 i, 1 c through the connectingsheet portions a3. Incidentally, a developed view thereof will beomitted.

The connected hollow structure in the developed state is used fordistribution as it is. However, when it is necessary to package articlesin a connected hollow structure immediately after the fabrication, aconnected hollow structure of a tray-like shape is formed as shown inFIG. 18 by placing the connected side structures 1 b, 1 b and theconnected front and rear structures 1 i, 1 c on the required portions ofthe connected bottom structure 1 a.

The connected side, front and rear structures 1 b, 1 i, 1 c may be fixedto the connected bottom structure 1 a by bonding or other appropriatemeans, as needed.

The connected hollow structure 1 in the eighth embodiment is used as acontainer or box for carrying or transporting fishery products, frozenfood or the like by shrink-packing the whole connected hollow structure1 with a shrink film along the external shape of the connected hollowstructure 1, for instance. Further, the whole connected hollow structuremay be shrink-packed even in its developed state. Thus, it is possibleto enhance heat-insulation, humidity-resistance and water-tightness ofthe container by shrink-packing the connected hollow structure in thismanner.

The connected hollow structure in the eighth embodiment may be also usedas a packaging frame structure, which also serves as a cushioningmaterial for packaging articles by partly inserting such articles intothe connected hollow structure, without being shrink-packed as describedabove.

Further, instead of the above procedure of fabrication, the connectedhollow structure 1 may be fabricated by individually forming thestructures 1 a, 1 b, 1 c, 1 i, and then connecting or fixing thesestructures together as shown in FIG. 18.

Other respects of the constitution, functions and effects of theconnected hollow structure in the eighth embodiment are substantiallysimilar to those of the connected hollow structure in the fifthembodiment, and hence, the description thereof will be omitted.

(Ninth embodiment)

FIG. 20 shows a packaging member formed of a connected hollow structurein a ninth embodiment wherein the connected hollow structure 1 has agenerally rectangular gutter-like shape and is composed of a connectedbottom structure 1 a, and a pair of connected side structures 1 c, 1 cformed on both sides of the connected bottom structure 1 a as one body,and a channel-like portion 1 j is formed in the center of the connectedhollow structure so as to extend in the lengthwise direction of hollowstructures 11, 12.

First and second hollow structures 11, 12 included in the connectedbottom structure 1 a have a rectangular equilateral triangular section,and first and second hollow structures 11, 12 included in the connectedside structures 1 b, 1 b have a right-angled triangular section which islarger in height and narrower in base width than the hollow structures11, 12 of the connected bottom structure 1 a. Thus, the upper portion ofeach connected side structure 1 b forms a projection 14 b projectingupwards from the upper surface of the connected bottom structure 1 athrough a certain difference in level.

The connected hollow structure 1 in the ninth embodiment is fabricatedas follows. Firstly, as shown in FIG. 22, while a sheet a of apredetermined width is being delivered, concave folds a1, a1 and convexfolds a2, a2 are formed on the sheet a from its leading end so as toextend in the transverse direction of the sheet in an alternatearrangement and in parallel with each other according to the sectionalheight and base width of the hollow structures 11, 12 of the structures1 a, 1 b.

A fold a13 is formed along the border between a sheet portion 1 a′,which forms the connected bottom structure 1 a of FIG. 20, and a sheetportion 1 b′, which forms one connected side structure 1 b. Further,convex folds a2, a2 and concave folds a1, a1 are formed in an alternatearrangement on a sheet portion 1 b′, which forms the other connectedside structure 1 b, and the sheet portions 1 a′, 1 b′.

The required surface of the sheet a is coated with glue (i.e., anadhesive) along the folds a1, a2.

Subsequently, while the sheet a is being folded along the folds a1, a2and a13 in sequence to form the hollow structures 11, 12, the edges ofthe hollow structures 11 adjacent to each other and those of the hollowstructures 12 adjacent to each other respectively are bonded together,and the inner surfaces of the structures 1 b, 1 b and the edges ofboth-side upper portions of the hollow structure 1 a are bondedtogether. Then, the sheet a is cut as required. Incidentally, thefolding of the sheet a starts according to the direction as shown by anarrow d in FIG. 20.

The connected hollow structure 1 in the ninth embodiment is suitable foruse as a packaging frame structure, which also serves as a cushioningmaterial for packaging an article by partially inserting such an articleinto the channel-shaped portion 1 j.

Alternately, it is possible to form a tray-shaped connected hollowstructure as shown in FIG. 18 by fixing other connected structures (notshown) to both ends of the connected hollow structure 1.

The connected hollow structure 1 in the ninth embodiment is designedsuch that the width of the base of each of the hollow structures 11, 12in the connected side structures 1 b, 1 b having a large sectionalheight is reduced in inverse proportion to the sectional height, and thehollow structures 11, 12 in the connected side structures 1 b, 1 b areformed at a small pitch. Thus, there is not a great difference betweenwithstanding strength against a planar force applied to the connectedside structures 1 b, 1 b and withstanding strength against a planarforce applied to the connected bottom structure 1 a.

Other respects of the constitution, functions and effects of theconnected hollow structure in the ninth embodiment are substantiallysimilar to those of the connected hollow structure in the eighthembodiment, and hence, the description thereof will be omitted.

(Tenth embodiment)

FIG. 21(A) shows a modification of the connected hollow structure in theninth embodiment.

A connected hollow structure 1 in a tenth embodiment is substantiallysimilar to the connected hollow structure in the ninth embodiment,except that first hollow structures 11 of a right-angled triangularsection in the tenth embodiment are formed at both side portions of aconnected bottom structure 1 a, and hollow structures 11, 12 of anisosceles triangular section in the tenth embodiment are formed atportions other than both side portions of the connected bottom structure1 a.

Since the connected bottom structure 1 a is formed in this manner, it isnot necessary to form the fold a13 on the sheet a between the sheetportion 1 a′ and either sheet portion 1 b′ shown in FIG. 22. Thus, nooverlap portion 10′ of the sheet as shown in FIG. 22 is formed betweenthe connected bottom structure 1 a and one connected side structure 1 b,and as a result, a one-fold connected hollow structure is whollyfabricated from a single sheet.

Other respects of the constitution, functions and effects of theconnected hollow structure in the tenth embodiment are substantiallysimilar to those of the connected hollow structure in the ninthembodiment, and hence, the description thereof will be omitted.

(Eleventh embodiment)

FIG. 21(B) shows another modification of the connected hollow structurein the ninth embodiment.

A connected hollow structure 1 in an eleventh embodiment is composed ofa pair of connected side structures 1 b, 1 b having hollow structures11, 12 higher than those of a connected bottom structure 1 a, and theconnected bottom structure 1 a formed in the center between theconnected side structures in the vertical direction through adjustingsheet portions a14, and channel-shaped portions 1 j, 1 j are formed onboth upper and lower surfaces of the connected bottom structure 1 a.

Thus, the upper and lower portions of each connected side structure 1 bform projections 14 b projecting from the upper and lower surfaces ofthe connected bottom structure through a certain difference in level.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the eleventh embodiment aresubstantially similar to those of the connected hollow structure in theninth embodiment, and hence, the description thereof will be omitted.

(Twelfth embodiment)

FIGS. 23 and 24 respectively show a connected hollow structure 1 of atwelfth embodiment is composed of two gutter-like connected structures 1k, 1 k each having a substantially smooth right-angled circumferenceincluding a longitudinal center formed into a chamfered side surface 1m, and an inner surface in of a polygonal section close to asemi-circular shape. The two gutter-like connected structures 1 k, 1 kare connected together through a base sheet portion 14′ which forms thebase surface of one second hollow structure 12 upon completion.

The gutter-like connected structures 1 k have the same structure and areof the same size, and the first and second hollow structures 11, 12adjacent to each other as the components of the gutter-like connectedstructures have a triangular section, and are not similar to each other.The total sum of angles of outward corner portions 13 of the firsthollow structures 11 is smaller than that of angles of inward cornerportions 13 of the second hollow structures 12. Further, the shape andsize of the hollow structures 11, 12 are designed to be fit to form thegutter-like connected structures 1 k as shown in the drawings.

The second hollow structure 12 positioned on the free end of eachgutter-like connected structure 1 k has a right-angled triangularsection such that the inclined side wall 15 of the first hollowstructure 11 adjacent to the second hollow structure 12 on the free endforms the inclined side surface of the second hollow structure 12.

The connected hollow structure 1 in the twelfth embodiment is fabricatedas follows. Firstly, while a sheet (not shown) of a predetermined widthis being delivered, convex folds and concave folds are sequentiallyformed on the sheet in parallel to each other in a required order atintervals according to the size of the hollow structures 11, 12, and therequired surface of the sheet is coated with glue along the folds.

Subsequently, while the sheet is being folded along the folds accordingto the direction as shown by an arrow e in FIG. 23, the edges of thehollow structures 11 adjacent to each other and those of the hollowstructures 12 adjacent to each other are respectively bonded together,and the sheet is cut.

According to the above procedure, the connected hollow structure 1 isformed, in which the hollow structures 11, 12 adjacent to each otherhave common side walls, which form the border between the hollowstructures adjacent to each other and are comprised of a single sheet soas to take the shape resembling a unicursal figure in section, and thesheet as the material of the connected hollow structure is notoverlapped on any surfaces of the hollow structures 11, 12.

The connected hollow structure 1 in a semi-developed state as shown inFIG. 23 is used for displaying bottles or like cylindrical articles byplacing such articles on the inner surfaces in.

Otherwise, in case of packaging bottles or like articles having acylindrical portion, a cylindrical connected hollow structure 1 isformed by guiding such articles to be packaged to the inside of eithergutter-like connected structure 1 k, and then fitting the gutter-likeconnected structures 1 k, 1 k face to face with each other such that theinside edges of the first hollow structures 11, 11 adjacent to thecenter base sheet portion 14′ are brought face to face with each other,and the second hollow structures 12, 12 on the free ends of thegutter-like connected structures 1 k, 1 k are brought face to face witheach other so as to form a second hollow structure 12 of a rectangularequilateral triangular section in the confronting portion of the firsthollow structures. Then, the connected hollow structure 1 in this stateis packed in a rectangular parallel piped box (not shown).

The connected hollow structure 1 in the twelfth embodiment takes theshape of a truss in section on the whole, and therefore, enablessufficient protection of packaged articles, since, even when an externalforce is suddenly applied to a portion of the circumference in the stateas shown in FIG. 24, the side walls 15 common to the hollow structures11, 12 are bent and absorb such an external force.

Further, the connected hollow structure 1 takes the shape of a truss insection on the whole, and therefore, shows high withstanding strengtheven in case of using a thin sheet as the material of the connectedhollow structure.

Furthermore, the connected hollow structure 1 in this embodiment has anappearance of a substantially quadrangular section, and therefore, issuitably used for packaging one or a plurality of bottles or likearticles having a cylindrical portion at a time.

According to the connected hollow structure 1 in this embodiment, thegutter-like connected structures 1 k, 1 k may be separated from eachother.

Other respects of the constitution, functions and effects of theconnected hollow structure in the twelfth embodiment are substantiallysimilar to those of the connected hollow structure in the firstembodiment, and hence, the description thereof will be omitted.

(Thirteenth embodiment)

FIG. 25 partially shows a connected hollow structure 1 of a thirteenthembodiment which is formed such that first hollow structures 11 of anisosceles triangular section and second hollow structures of anisosceles triangular section, which is equal in height to and wider inbase (i.e., partial circumferences 14) than the first hollow structures11 (i.e., a corner portion 13 of each second hollow structure 12 islarger than that of each first hollow structure 11) are alternatelyarranged in alternately inverted positions.

Thus, a cylindrical connected hollow structure or a connected hollowstructure of a circular-arc section, in which the bottoms of the firsthollow structures 11 form the inner surface, is formed by continuouslyarranging the hollow structures 11, 12.

The sides (edges) of the partial circumferences 14 of the hollowstructures 11 adjacent to each other and the sides of the partialcircumferences 14 of the hollow structures 12 adjacent to each other arerespectively connected together by bonding, and the hollow structures11, 12 adjacent to each other have the inclined side walls 15 in common.

The connected hollow structure 1 in the thirteenth embodiment in case ofhaving a cylindrical shape is used as a frame structure for packagingand protecting bottles or like articles having a cylindrical orcylindroid portion.

On the other hand, the connected hollow structure 1 in the thirteenthembodiment in case of having a circular gutter-like shape is used as aframe structure for displaying bottles or like articles having acylindrical or cylindroid portion by placing such articles on thecircular-arc inner portion. In addition, a combination of two connectedhollow structures 1 is suitable for use as a frame structure forpackaging and protecting such articles.

The connected hollow structure 1 in this embodiment shows highwithstanding strength against an external force applied in thecircumferential direction, and also functions as a cushion, since, whena sudden external force is partially applied in the circumferentialdirection, the inclined side walls 15 are bent and absorb such anexternal force.

Other respects of the functions and effects of the connected hollowstructure in the thirteenth embodiment are substantially similar tothose of the connected hollow structure in the twelfth embodiment, andhence, the description thereof will be omitted.

(Fourteenth embodiment)

FIG. 26 partially shows a connected hollow structure 1 of a fourteenthembodiment which is composed of first and second hollow structures 11,12 of a triangular section close to a right-angled triangular shape, andthe first and second hollow structures 11, 12 are designed to have thesame shape and be of the same size.

The width of the partial circumference (i.e., an angle of a cornerportion 13) of each hollow structure 11 is designed to be smaller thanthat of the partial circumference 14 (i.e., an angle of a corner portion13) of each hollow structure 12. The partial circumferences 14 of thehollow structures 11 form a slightly-concave circular-arc surface, andthe partial circumferences 14 of the hollow structures 12 form aslightly-convex circular-arc surface.

The connected hollow structure 1 in this embodiment, in the case of acylindrical or circular gutter-like overall shape, has an inner surfaceof a substantially-cylindrical or circular-arc shape. Thus, when theconnected hollow structure 1 in this embodiment is used for packagingbottles or like articles having a cylindrical or cylindroid portion, theinner surface of this connected hollow structure 1 sufficiently fits theexternal shape of such articles to be packaged.

In comparison with the connected hollow structure 1 in the thirteenthembodiment, the connected hollow structure 1 in the fourteenthembodiment shows slightly lower withstanding strength against anexternal force in the circumferential direction, while it shows moreflexible elasticity.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the fourteenth embodiment aresubstantially similar to those of the connected hollow structure in thethirteenth embodiment, and hence, the description thereof will beomitted.

(Fifteenth embodiment)

FIG. 27 shows a connected hollow structure in a fifteenth embodimentaccording to the present invention wherein the connected hollowstructure 1 is formed by folding a single sheet along concave folds andconvex folds formed on the sheet so as to extend in the transversedirection of the sheet in parallel to each other. First hollowstructures 11 of a right-angled triangular section and different inheight, and second hollow structures 12 including hollow structures of aright-angled triangular section and those of a section other than aright-angled triangular section are alternately arranged in analternately inverted positions, and connected together by bonding.

The connected hollow structure 1 has a substantially smooth lowersurface formed by connecting the partial circumferences 14 of the firsthollow structures 11, while its upper surface formed by connecting thepartial circumferences 14 of the second hollow structures 12 has arising portion 14 a gradually rising from one end to the other so as tofit the shape of an article (not shown) to be packaged.

The connected hollow structure 1 in this embodiment varies inwithstanding strength against a planar force applied to each portion,since each first hollow structures 11 has a substantially uniform basewidth (i.e., the width of the partial circumference 14), and the heightof the first hollow structure 11 gradually varies. When the connectedhollow pressure 1 is exposed to a planar force of not less than apredetermined value, the vertical side walls 15 common to the adjacentfirst and second hollow structures 11, 12 are bent and absorb such apressure.

The connected hollow structure 1 in this embodiment is suitable for useas a support table for an article having a bottom fit to the shape ofthe upper surface of the connected hollow structure 1, or a framestructure for packaging such an article.

Other respects of the constitution, functions and effects of theconnected hollow structure in the fifteenth embodiment are substantiallysimilar to those of the connected hollow structure in the firstembodiment, and hence, the description thereof will be omitted.

(Sixteenth embodiment)

FIG. 28 shows a connected hollow structure of a sixteenth embodimentaccording to the present invention wherein the connected hollowstructure 1 is formed, substantially similarly to the connected hollowstructure 1 in the fifteenth embodiment, such that its upper surfaceformed by connecting the partial circumferences 14 of second hollowstructures 12 has a rising portion 14 a gradually rising from one end tothe other so as to substantially fit the shape of the bottom of anarticle to be packaged.

On the other hand, the connected hollow structure 1 in the sixteenthembodiment is different from the connected hollow structure in thefifteenth embodiment in that a pitch of the hollow structures 11, 12formed in the rising portion 14 a (i.e., the width of the partialcircumferences 14 forming the bottom of the hollow structures 11) ismade smaller in proportion to the scale of rising.

According to the connected hollow structure 1 in this embodiment, sincethe pitch of the hollow structures 11, 12 is made smaller in proportionto the scale of rising on the upper surface as described above,withstanding strength against a planar force is easily made uniform ineach portion of the connected hollow structure 1.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the sixteenth embodiment aresubstantially similar to those of the connected hollow structure in thefifteenth embodiment, and hence, the description thereof will beomitted.

(Seventeenth embodiment)

FIG. 29 shows a connected hollow structure in a seventeenth embodimentaccording to the present invention wherein the connected hollowstructure 1, is composed of a connected bottom structure 1 a, aconnected side structure 1 b uprightly placed on one side of theconnected bottom structure 1 a, and a connected rear structure 1 cuprightly placed on the rear of the connected bottom structure 1 a.

The connected bottom structure 1 a and the connected rear structure 1 care formed as one body, and the upper surface of the connected rearstructure 1 c has a projection 14 b projecting from the upper surface ofthe end of the connected bottom structure 1 a through a difference inlevel.

The connected side structure 1 b is formed separately from the connectedbottom structure 1 a, and then bonded to one side of the connectedbottom structure 1 a.

The connected bottom, side and rear structures 1 a, 1 b, 1 c are formedby alternately arranging their first and second hollow structures 11, 12of a triangular section in alternately inverted positions, and thenconnecting these hollow structures together.

The upper surface of the connected bottom structure 1 a is formed byconnecting the partial circumferences 14, which form the upper surfaceof the second hollow structures 12, together, and has front and centerrising portions 14 a gradually rising from portions other than the frontand center portions. A pitch of the hollow structures 11, 12 formed inthese rising portions 14 a is made small.

The connected bottom structure 1 a has a smooth bottom and a narrowcenter portion.

The connected side structure 1 b has a center rising portion on itsupper surface portion other than the left and right ends in the drawingso as to extend substantially in parallel to the rising portion 14 a.

The hollow structures 11, 12 included in the connected rear structure 1c are higher than those included in the connected bottom structure 1 aadjacent to the connected side structure 1 c.

The connected hollow structure 1 in this embodiment has a special innershape defined by the connected bottom structure 1 a, the connected sidestructure 1 b and the connected rear structure 1 c, and therefore, issuitable for use as a corner protection frame for protecting an article(not shown) partially having a corner portion fit for the inner surfaceshape of the connected hollow structure by bringing such a cornerportion of the article into contact with the inner surface of theconnected hollow structure.

Since the pitch of the hollow structures 11, 12 formed in the risingportion 14 a of the connected bottom structure 1 a is made smaller inproportion to the scale of rising, there is no great difference inwithstanding strength against a planar force received by each portion ofthe connected bottom structure 1 a.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the seventeenth embodiment aresubstantially similar to those of the connected hollow structure in thefifth embodiment, and hence, the description thereof will be omitted.

(Eighteenth embodiment)

FIG. 30 shows a connected hollow structure in an eighteenth embodimentaccording to the present invention wherein the connected hollowstructure 1 is formed such that first hollow structures 11 have atriangular section including a corner portion 13 directed upwards and apartial circumference 14 forming a base and facing the lower surface,and second hollow structures 12 of a triangular section including acorner portion 13 directed downwards and a partial circumference facingthe upper surface are alternately arranged, and is comprised of a singlesheet as a whole so as to take the shape resembling a unicursal figurein section.

The first hollow structures 11 have an isosceles triangular section andare of the same size, while the second hollow structures 11 includehollow structures of an isosceles triangular section and those of aright-angled triangular section in the ratio of 1:2. The second hollowstructures 12 are formed in an alternate arrangement such that thesecond hollow structures 12, 12 of the right-angled triangular sectionare placed in a reverse position next to the second hollow structure ofthe isosceles triangular section.

The partial circumferences 14 on the upper side of the second hollowstructures 12 of the right-angled triangular section adjacent to eachother are inclined in the reverse direction substantially in the shapeof a letter V, and the partial circumferences 14 of the second hollowstructures 12 of the right-angled triangular section partially projectso as to overhang the adjacent second hollow structure 12 of theisosceles triangular section.

The first hollow structures 11, 11 adjacent to each other are connectedtogether by bonding in a portion of the corner portion 13 of each secondhollow structure 12 positioned between the first hollow structuresadjacent to each other, and the second hollow structures 12, 12 adjacentto each other are connected together by bonding in a portion of thecorner portion 13 of each first hollow structure 11 positioned betweenthe second hollow structures adjacent to each other.

The partial circumferences 14 of the first hollow structures 11 areconnected together to form a smooth lower surface of the connectedhollow structure, while the partial circumference 14 of the secondhollow structure of the right-angled triangular section and that of theadjacent second hollow structure of the isosceles triangular section arenot connected together.

The first hollow structure 11 and the adjacent second hollow structure12 of the isosceles triangular section, and the first hollow structure11 and the adjacent second hollow structures 12, 12 of the right-angledtriangular section on both sides of the first hollow structurerespectively have all the side walls 15 in common. On the other hand,the second hollow structure 12 of the right-angled triangular sectionand the adjacent first hollow structure 11 on one side of the secondhollow structure merely partially have the side walls between both thehollow structures in common as viewed from the side of the second hollowstructures 12.

The connected hollow structure 1 in this embodiment is formed asdescribed above, and therefore, shows relatively low withstandingstrength against a planar force, while it shows flexible elasticity onthe whole, since, when the connected hollow structure 1 receives aplanar force of not less than a certain extent, the second hollowstructures 12 of the right-angled triangular section overhanging thesecond hollow structures 12 of the isosceles triangular section arepartly bent.

Then, the second hollow structures 12 of the right-angled triangularsection overhanging the second hollow structures 12 of the isoscelestriangular section become partly unable to withstand a load, and as aresult, are collapsed, and the collapsed portion is overlapped on thehorizontal part 14 of the second hollow structures 12 of the isoscelestriangular section. At this time, since the second hollow structures 12of the right-angled triangular section are transformed into an isoscelestriangular section of a size similar to that of the other second hollowstructures 12, the connected hollow structure 1 after transformationshows high withstanding strength against a planar force, similarly tothe connected hollow structure in the first embodiment, for instance.

Namely, at an initial stage of the application of a planar force to theconnected hollow structure 1, the second hollow structures 12 of theright-angled triangular section are transformed and absorb such theplanar force. At a stage of the application of a far higher planarforce, the side walls of the hollow structures 11, 12 adjacent to eachother are bent and absorb such a planar force. In this manner, theconnected hollow structure 1 in this embodiment functions as a cushionin two stages.

Thus, the connected hollow structure 1 in this embodiment is suitablefor use as a packaging member which needs the cushioning properties intwo stages.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the eighteenth embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Nineteenth embodiment)

FIG. 31 shows a connected hollow structure 1 of a nineteenth embodimentwhich is formed such that first and second hollow structures 11, 12 ofan isosceles triangular section and of the same size are densely andalternately arranged in alternately inverted positions, namely, suchthat the first, second and first hollow structures 11, 12, 11 arearranged in this order in alternately inverted positions, and anothersecond hollow structure, which is equal in a sectional shape to and islarger in sectional size than the first hollow structures, is arrangednext to a group of these small-sized hollow structures in an inverseposition.

The first hollow structures 11 adjacent to each other are connectedtogether by bonding at a portion of the corner portion 13 of each secondhollow structure 12 positioned between the first hollow structures 11adjacent to each other, and the second hollow structures 12 adjacent toeach other are connected together by bonding in a portion of the cornerportion 13 of each first hollow structure 11 positioned between thesecond hollow structures 12 adjacent to each other.

The partial circumferences 14 of the first hollow structures 11 areconnected together to form a smooth plane, while the partialcircumferences 14 of the second hollow structures 12 are not connectedtogether.

The second hollow structures 12 positioned at opposing ends of theconnected hollow structure 1 have the sectional shape of a right-angledtriangle equivalent to the half of the sectional shape of thelarge-sized hollow structure 12.

The first hollow structures 11 and the small-sized second hollowstructures 12 share in common all the side walls between the first andsecond hollow structures adjacent to each other, while the first hollowstructures 11 and the large-sized second hollow structures 12 partlyshare in common the side walls between the first and second hollowstructures adjacent to each other.

The connected hollow structure 1 in the nineteenth embodiment isfabricated as follows. Firstly, predetermined convex folds and concavefolds are formed on a sheet (not shown) of a predetermined width so asto extend in the transverse direction of the sheet, and the folding ofthe sheet starts from the leading end of the sheet according to thedirection as shown by an arrow g in FIG. 31 to form the hollowstructures.

Namely, the hollow structures 12 and 11 are formed in alternatelyinverted positions by folding the sheet according to the direction asshown by the arrow g in FIG. 31.

At this time, the first hollow structures 11 are bonded together in aportion of the corner portion of each second hollow structure 12positioned between the first hollow structures adjacent to each other,and the large-sized second hollow structures 12 and the small-sizedsecond hollow structures 12 are bonded together such that one side ofthe partial circumference 14 of each small-sized hollow structure isbonded to a portion of the side wall 15 of each large-sized secondhollow structure.

The connected hollow structure 1 formed as described above takes theshape resembling a unicursal figure in section, and has no sheet overlapportion other than the bonded portions, and therefore, its apparentspecific gravity is extremely small.

Although the connected hollow structure 1 in this embodiment has apanel-like shape of substantially uniform apparent thickness T, it showsmore flexible elasticity against a planar force than that of theconnected hollow structure in the first embodiment, since the partialcircumferences 14 of the large-sized second hollow structures 12 projectupwards from the partial circumferences 14 of the small-sized secondhollow structures 12.

Other respects of the functions and effects of the connected hollowstructure 1 in the nineteenth embodiment are substantially similar tothose of the connected hollow structure in the first embodiment, andhence, the description thereof will be omitted.

(Twentieth embodiment)

FIG. 32 shows a connected hollow structure in a twentieth embodimentaccording to the present invention wherein the connected hollowstructure is formed such that first hollow structures 11 of an isoscelestriangular section, second hollow structures 12 of an isoscelestriangular section including a base surface in common with the inclinedsurfaces of the first hollow structures 11, large-sized first hollowstructures 11 of an isosceles triangular section substantially equal insectional height to and larger in base width than the first hollowstructures, and other second hollow structures 12 equal in sectionalshape and size to the aforementioned second hollow structures 12 andreversed to each other are alternately arranged in this order in analternately inverted positions.

The first hollow structure 11 positioned at each end of the connectedhollow structure 1 has a right-angled triangular section.

Both sides of the partial circumference 14 of each first hollowstructure 11 having a narrow base (i.e., partial circumference 14) arebonded to portions of the inclined sides of the first hollow structures11 having a wide base, and the partial circumferences of the firsthollow structures having the wide base project downward from the bottomof the first hollow structures having the narrow base.

The connected hollow structure 1 has a corrugated upper surface,although the upper surface of the connected hollow structure 1 is formedby connecting the partial circumferences 14 of the second hollowstructures 12 together.

The connected hollow structure 1 in the twentieth embodiment isfabricated as follows. Firstly, predetermined convex folds and concavefolds are formed on a sheet (not shown) of a predetermined width so asto extend in the transverse direction of the sheet, and the folding ofthe sheet starts from the leading end of the sheet according to thedirection as shown by an arrow h in FIG. 32 to form the hollowstructures.

Namely, the connected hollow structure 1 is fabricated by sequentiallybonding the edges of the first hollow structures 11 and those of thesecond hollow structures 12, together while folding the sheet so as toform the first and second hollow structures 11, 12 in an alternatearrangement according to the direction as shown by the arrow h in FIG.32.

The connected hollow structure 1 formed as described above takes theshape resembling a unicursal figure in section. In addition, thesurfaces of the hollow structures 11, 12 have no sheet overlap portionother than the bonded portions, and the whole apparent specific gravityof the connected hollow structure 1 is extremely small.

In comparison with the connected hollow structure of the firstembodiment, the connected hollow structure 1 in the twentieth embodimentshows lower withstanding strength against a planar force, while it showsmore flexible elasticity.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the twentieth embodiment aresubstantially similar to those of the connected hollow structure in thenineteenth embodiment, and hence, the description thereof will beomitted.

(Twenty-first embodiment)

FIG. 33 partially shows a connected hollow structure 1 of a twenty-firstembodiment which is formed such that first hollow structures of aright-angled triangular section and of the same size, and second hollowstructures 12 of a quadrangular section and of the same size arearranged alternately and densely. Each second hollow structure 12 has asectional shape including two right-angled portions and an inclined sidewall, and its section takes the special shape.

Each first hollow structure 11 is formed such that an acute-angledcorner portion 13 is directed toward the upper surface, and a partialcircumference 14 forming a base faces the lower surface. Each secondhollow structure 12 is formed such that an acute-angled corner portion13 is directed toward the lower surface, and a partial circumference 14between the right-angled corner portions on both sides faces the uppersurface.

The partial circumferences 14 of the first hollow structures 11 adjacentto each other are bonded together in a portion of the corner portion 13of each second hollow structure 12 positioned between the adjacent firsthollow structures adjacent to each other, and the partial circumferences14 of the second hollow structures 12 adjacent to each other are bondedtogether.

The vertical side walls of the second hollow structures 12 adjacent toeach other are overlapped with each other in upper end portions of thesecond hollow structures so as to extend from the corner portions 13 ofthe first hollow structures 11 toward the upper ends of the secondhollow structures. The sheet forming the connected hollow structure isbonded in an overlap state in the upper end portions of the secondhollow structures.

The connected hollow structure 1 in the twenty-first embodiment isfabricated as follows. Firstly, while a sheet (not shown) is beingdelivered, convex folds and concave folds are formed on the sheet so asto extend in the transverse direction of the sheet according to thesectional shape of the hollow structures 11, 12, and the requiredsurface of the sheet 1 is sequentially coated with glue along the folds.

Subsequently, while the sheet is being folded along the folds, therequired portions of the sheet are bonded together to sequentially formthe first and second hollow structures 11, 12 in an alternatingarrangement. After the connected hollow structure 1 of the size meetingthe design has been fabricated, the sheet is cut. Incidentally, thesheet may be cut in advance depending on the design.

The connected hollow structure 1 formed as described above is comprisedof a single sheet and takes the shape resembling a unicursal figure insection.

In comparison with the connected hollow structure 1 in the firstembodiment, the apparent specific gravity of the connected hollowstructure 1 in the twenty-first embodiment becomes slightly smaller,whereas the hollow structures 11, 12 of the connected hollow structurein this embodiment are connected together more firmly, since theconnected hollow structure in this embodiment has sheet overlapportions, scanty as they are.

When the connected hollow structure 1 receives a planar force of notless than a predetermined value, the vertical side walls 15 and inclinedside walls 15 common to the hollow structures 11, 12 are bent, andtherefore show elasticity in some degree to make it possible to absorbsuch a force.

Other respects of the constitution, purposes, functions and effects ofthe connected˜hollow structure 1 in the twenty-first embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Twenty-second embodiment)

FIG. 34 shows a connected hollow structure 1 in a twenty-secondembodiment which is formed such that first hollow structures 11 of aright-angled triangular section, second hollow structures 12 of aquadrangular (special) section, other first hollow structures 11 of aquadrangular section, and other second hollow structures 12 of aright-angled triangular section are alternately arranged in this order.

Each first hollow structure 11 is formed such that an acute-angledcorner portion 13 is directed toward the upper surface, and a horizontalpartial circumference 14 faces the lower surface. Each second hollowstructure 12 is formed such that an acute-angled corner portion 13 isdirected toward the lower surface, and a horizontal partialcircumference 14 faces the upper surface.

The sides of the partial circumferences 14 of the first hollowstructures 11 adjacent to each other are connected together by bonding,and the sides of the partial circumferences 14 of the second hollowstructures 12 adjacent to each other are connected together by bonding.The connected hollow structure I has a panel-like shape to give upperand lower smooth surfaces and to be substantially uniform in apparentthickness T, and takes a shape resembling a unicursal figure in section.

A lower portion of each first hollow structure 11 of the quadrangularsection is bonded to a lower portion of each adjacent first hollowstructure 11 of the right-angled triangular section in apartially-overlapped state, and an upper portion of each second hollowstructure 12 of the quadrangular section is bonded to an upper portionof each adjacent first hollow structure 11 of the right-angledtriangular section in a partially overlapped state.

The fabricating method, and other respects of the constitution,functions and effects of the connected hollow structure in thetwenty-second embodiment are substantially similar to those of theconnected hollow structure in the twenty-first embodiment, and hence,the description thereof will be omitted.

(Twenty-third embodiment)

FIG. 35 shows aa connected hollow structure 1 in a twenty-thirdembodiment which is formed such that first hollow structures 11 of aquadrangular (special) section and of the same size and second followstructures equal in shape and size to the first hollow structures 11 arearranged alternately.

Each first hollow structure 11 is formed such that an acute-angledcorner portion 13 is directed toward the upper surface, and a horizontalpartial circumference 14 faces the lower surface. Each second hollowstructure 12 is formed such that an acute-angled corner portion 13 isdirected toward the lower surface and a horizontal partial circumference14 faces the upper surface.

The sides of the partial circumferences 14 of the first hollowstructures 11 adjacent to each other are connected together by bonding,and the sides of the partial circumferences 14 of the second hollowstructures 12 adjacent to each other are connected together by bonding.Then, the connected hollow structure 1 has a panel-like shape with upperand lower smooth surfaces, is substantially uniform in apparentthickness T, and takes a shape resembling a unicursal figure in section.

The first hollow structures 11 adjacent to each other and the secondhollow structures 12 adjacent to each other are respectively bondedtogether in a partially-overlapped state in portions of the verticalside walls 15.

The fabricating method and other respects of the constitution, functionsand effects of the connected hollow structure in the twenty-thirdembodiment are substantially similar to those of the connected hollowstructure in the twenty-first embodiment, and hence, the descriptionthereof will be omitted.

(Twenty-fourth embodiment)

FIG. 36 partially shows a connected hollow structure 1 in atwenty-fourth embodiment is composed of a large number of laterallyarranged first hollow structures 11 of a pentagonal section and of thesame size, and a large number of second hollow structures 12 of anisosceles triangular section and of the same size.

Each first hollow structure 11 is formed such that an upper cornerportion 13 is directed toward the upper surface, and a partialcircumference 14 forming the lower surface faces the lower surface, andeach second hollow structure 12 is formed such that a corner portion 13is directed toward the lower surface and a partial circumference 14faces the upper surface.

The sides of the partial circumferences 14 forming the bottom of thefirst hollow structures 11, 11 adjacent to each other are connectedtogether by bonding, and the sides of the partial circumferences 14 ofthe second hollow structures 12, 12 adjacent to each other are connectedtogether by bonding. Since the partial circumferences 14 of the firsthollow structures 11 and those of the second hollow structures 12respectively form horizontal planes, the upper and lower surfaces of theconnected hollow structure 1 are formed horizontally, and the connectedhollow structure 1 has a panel-like shape which is uniform in apparentthickness.

The first and second hollow structures 11, 12 adjacent to each otherhave share in common the inclined side walls 15, which form each cornerportion 13.

The connected hollow structure 1 in the twenty-fourth embodiment isfabricated as follows. Firstly, while a sheet (not shown) of apredetermined width is being delivered, convex folds and concave foldsare sequentially formed on the sheet at intervals according to the sizeof the hollow structures 11, 12 in a required order, and the requiredsurface of the sheet is coated with glue along the folds.

Subsequently, while the sheet is being folded along the folds so as tostart the folding of the sheet according to the direction as shown by anarrow j in FIG. 36, the required edges of the hollow structures arebonded together, and the sheet is cut.

According to the above procedure, it is possible to form the connectedhollow structure 1, in which the hollow structures 11, 12 have commonside walls 15 forming the border between the adjacent hollow structures,and are comprised of a single sheet so as to take a shape resembling aunicursal figure in section, and the sheet material of the connectedhollow structure is overlapped on the vertical sides of the hollowstructures 11.

In comparison with the connected hollow structure in the firstembodiment, the connected hollow structure 1 in the twenty-fourthembodiment shows lower withstanding strength against a planar force,while it shows more flexible elasticity, since, when the connectedhollow structure 1 is exposed to a planar force of not less than apredetermined value, the common side walls forming the corner portions13 of the hollow structures 11, 12 are bent.

Thus, the connected hollow structure in the twenty-fourth embodiment issuitable for use as a cushioning material for packaging, and is suitablyused for keeping or packaging linear fluorescent lamps or like articlesby inserting such articles into the hollow portions of the hollowstructures 11.

Other respects of the functions and effects of the connected hollowstructure in the twenty-fourth embodiment are substantially similar tothose of the connected hollow structure in the first embodiment, andhence, the description thereof will be omitted.

(Twenty-fifth embodiment)

FIG. 37 shows a connected hollow structure 1 in a twenty-fifthembodiment which is formed such that first hollow structures 11 eachhave a corner portion 13 directed toward the upper surface and a partialcircumference 14 facing the lower surface, and second hollow structures12 each have a corner portion 13 directed toward the lower surface and apartial circumference 14 facing the upper surface, which corner portionsare alternately arranged.

The sides of the partial circumferences 14 of the first hollowstructures 11, 11 adjacent to each other are substantially horizontallyconnected together by bonding, and the sides of the partialcircumferences 14 of the second hollow structures 12, 12 adjacent toeach other are substantially horizontally connected together by bonding.Thus, the connected hollow structure 1 has a panel-like shapesubstantially uniform inapparent thickness T, and takes a shaperesembling a unicursal figure in section.

While the first hollow structure 11 at each end of the connected hollowstructure 1 has a right-angled triangular section of a small size, otherfirst hollow structures 11 have an isosceles triangular section of thesame size.

The second hollow structures 12 uniformly include hollow structures of apentagonal section of a slightly special shape, and those of anisosceles triangular section. The side walls of the second hollowstructures 12 of the pentagonal section and those of the second hollowstructures 12 of the isosceles triangular section are partiallyoverlapped with each other.

Since the corner portions 13 of the hollow structures 11, 12 are formedat the same angle, the connected hollow structure 1 in this embodimentis substantially equal in withstanding strength against a planar forceto the connected hollow structure in the first embodiment. Thus, whenthe connected hollow structure 1 is exposed to a planar force of notless than a predetermined value, the common side walls of the hollowstructures 11, 12 are bent, and as a result, show elasticity to absorbsuch a force.

The connected hollow structure 1 has both ends respectively formed intoa chamfered inclined side surface 15 a so as to round off the corner atboth ends.

Other respects of the functions and effects of the connected hollowstructure in the twenty-fifth embodiment are substantially similar tothose of the connected hollow structure in the first embodiment, andhence, the description thereof will be omitted.

(Twenty-sixth embodiment)

FIG. 38 partially shows a connected hollow structure 1 in a twenty-sixthembodiment as being composed of first hollow structures 11 and secondhollow structures 12. The first hollow structures 11 include hollowstructures of a pentagonal (special) section and of the same size, andthose of a quadrangular (special) section and of the same size in theratio of 1:2. Further, the second hollow structures 12 include hollowstructures of a right-angled triangular section and of the same size andthose of an isosceles triangular section and of the same size in theratio of 2:1.

A large number of first and second hollow structures 11, 12 as describedabove are formed in an alternate arrangement according to a certainrepetitive pattern as shown in FIG. 38.

The sides of the partial circumferences 14 of the first hollowstructures 11, 11 adjacent to each other are connected together bybonding so as to form a substantially horizontal plane, and the sides ofthe partial circumferences 14 of the second hollow structures 12, 12adjacent to each other are connected together by bonding so as to form asubstantially horizontal plane. Thus, the connected hollow structure 1has a panel-like shape which is substantially uniform in apparentthickness, and takes a shape resembling a unicursal figure in section.

There is no great difference in withstanding strength against a planarforce applied to each portion of the connected hollow structure 1 inthis embodiment, since the first and second hollow structures 11, 12 ofthe sectional shape as described above are formed in an alternatelywell-balanced arrangement according to a certain repetitive pattern. Theconnected hollow structure 1 withstands a planar force mainly with theside walls common to the adjacent first and second hollow structures 11,12.

The fabricating method, and other respects of the constitution,functions and effects of the connected hollow structure 1 in thetwenty-sixth embodiment are substantially similar to those of theconnected hollow structure in the first embodiment, and hence, thedescription thereof will be omitted.

(Twenty-seventh embodiment)

FIG. 39 partially shows a twenty-seventh embodiment as composed of firsthollow structures 11 and second hollow structures 12 respectivelyincluding hollow structures of a right-angled triangular section and ofthe same size and those of a pentagonal (special) section and of thesame size in the ratio of 2:1. Each of the hollow structures 11, 12 ofthe pentagonal section corresponds to two hollow structures 12 or 11 ofthe right-angled triangular section.

A large number of first and second hollow structures 11, 12 as describedabove are formed in an alternate arrangement according to a certainrepetitive pattern as shown in FIG. 39.

The sides of the partial circumferences 14 of the first hollowstructures 11, 11 adjacent to each other are connected together bybonding so as to form a substantially horizontal plane, and the sides ofthe partial circumferences 14 of the second hollow structures 12, 12adjacent to each other are connected together by bonding so as to form asubstantially horizontal plane. Thus, the connected hollow structure 1has a panel-like shape which is substantially uniform inapparentthickness, and takes a shape resembling a unicursal figure in section.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the twenty-seventh embodiment aresubstantially similar to those of the connected hollow structure in thetwenty-sixth embodiment, and hence, the description thereof will beomitted.

(Twenty-eighth embodiment)

FIG. 40 partially shows a connected hollow structure 1 in atwenty-eighth embodiment as being composed of first and second hollowstructures 1112 respectively including hollow structures of aquadrangular section and of the same size, and those of a pentagonalsection and of the same size in the ratio of 2:1. Each of the hollowstructures 11,12 of the pentagonal section corresponds to two hollowstructures 12 or 11 of the quadrangular section.

A large number of first and second hollow structures 11, 12 as describedabove are formed in an alternate arrangement according to a certainrepetitive pattern.

The sides of the partial circumferences 14 of the first hollowstructures 11, 11 adjacent to each other are connected together bybonding so as to form a substantially horizontal plane, and the sides ofthe partial circumferences 14 of the second hollow structures 12, 12adjacent to each other are connected together by bonding so as to form asubstantially horizontal plane. Thus, the connected hollow structure 1has a panel-like shape which is substantially uniform in apparentthickness, and takes a shape resembling a unicursal figure in section.

Other respects of the constitution, functions, and effects of theconnected hollow structure 1 in the twenty-eighth embodiment aresubstantially similar to those of the connected hollow structure in thetwenty-sixth embodiment, and hence, the description thereof will beomitted.

(Twenty-ninth embodiment)

FIG. 41 partially shows a connected hollow structure 1 in a twenty-ninthembodiment as being composed of first and second hollow structures 11,12 which respectively have a pentagonal section close to an isoscelestriangular shape and are of the same size. The first and second hollowstructures 11, 12 are formed in a dense and alternate arrangement and inalternately inverted positions.

The partial circumferences 14 of the first hollow structures 11, 11adjacent to each other are connected together by bonding so as to form asubstantially horizontal plane, and the partial circumferences 14 of thesecond hollow structures 12, 12 adjacent to each other are connectedtogether by bonding so as to form a substantially horizontal plane.Thus, the connected hollow structure 1 has a panel-like shape which issubstantially uniform in apparent thickness, and takes a shaperesembling a unicursal figure in section.

The connected hollow structure 1 in this embodiment shows highwithstanding strength against a planar force, even though its apparentspecific gravity is small, since each of the hollow structures 11, 12has a pentagonal section close to an isosceles triangular shape.Further, more uniform withstanding strength is shown in each part, sincethe hollow structures 11, 12 are of the same size.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the twenty-ninth embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Thirtieth embodiment)

FIG. 42(C) partially shows a connected hollow structure 1 in a thirtiethembodiment formed such that a right-angled corner portion of each secondhollow structure 12 of the right-angled triangular section at each endof the connected hollow structure 1 in the first embodiment is modifiedinto a chamfered inclined side surface 15 a.

It is possible to form a connected hollow structure having a rounded-offend, and to prevent the corner of each hollow structure 12 at both endsof the connected hollow structure 1 from being transformed or collapsedby forming the chamfered inclined side surface 15 a at the endsdescribed above.

A means for forming the chamfered inclined side surface 15 a at bothends of the connected hollow structure 1 in this manner may be appliedto a connected hollow structure in other embodiments having an overallpanel-like shape which is substantially uniform in apparent thickness,or a connected hollow structure having a gradually-rising portion formedon one surface, like the connected hollow structure in the fifteenthembodiment (See FIG. 27) or sixteenth embodiment (See FIG. 28).

(Thirty-first embodiment)

FIG. 42(D) shows a connected hollow structure 1 in a thirty-firstembodiment formed such that the hollow structure 12 at each end of eachprojection 14 b of the connected side structures 1 b, 1 b of theconnected hollow structure 1 in the ninth, tenth or eleventh embodiment(See FIGS. 20 and 21) is modified to have a chamfered inclined sidesurface 15 a extending in the lengthwise direction of the hollowstructure 12.

It is possible to form a connected hollow structure having a rounded-offend, and to prevent the corner of each hollow structure 12 at both endsof each projection 14 b of the connected hollow structure 1 from beingtransformed or collapsed by forming the chamfered inclined side surfacesa on each hollow structure positioned at the ends described above.

Further, when articles 2 to be packaged are inserted into a channel-likeportion 1 j of the connected hollow structure 1, the inner inclined sidesurfaces a of both the projections 14 b function as a guide for thearticles 2 when inserted, and enable the smooth insertion of thearticles.

(Thirty-second embodiment)

FIG. 43 shows a connected hollow structure 1 in a thirty-secondembodiment formed such that first and second hollow structures 11, 12included in a connected hollow structure having a gradually-risingportion 14 a formed on one surface, like the connected hollow structurein the fifteenth embodiment (See FIG. 27), have a pentagonal section,similarly to the connected hollow structure shown in FIG. 41.

(Thirty-third embodiment)

FIG. 44 shows a connected hollow structure 1 in a thirty-thirdembodiment formed such that a connected hollow structure having agradually-rising portion 14 a formed on one surface, like the connectedhollow structure in the thirty-second embodiment, is composed of firsthollow structures of a pentagonal section, and second hollow structuresof a triangular section.

Further, the upper corner portions of the first hollow structures 11 atboth ends of the connected hollow structure 1 in this embodiment aremodified into chamfered inclined side surfaces 15 a, 15 a.

When the connected hollow structure 1 having the rising portion 14 aformed on one surface like this embodiment is formed, the first andsecond hollow structures 11, 12 included in the connected hollowstructure 1 may take various shapes as shown in FIGS. 33 to 35 or 37,instead of the shapes described in the fifteenth, thirty-second andthirty-third embodiments.

(Thirty-fourth embodiment)

FIG. 45 shows a connected hollow structure in a thirty-fourth embodimentaccording to the present invention.

A connected hollow structure 1 in the thirty-fourth embodiment is formedsuch that laterally-arranged first hollow structures 11 of aquadrangular (or parallelogram) section and of the same size, and secondhollow structures 12 of a triangular section and of the same size on theupper side of the first hollow structures are connected together in analternate arrangement.

Each first hollow structure 11 is formed such that a corner portion 13is directed toward the upper surface, and a partial circumference 14composed of two side surfaces faces the lower surface. Each secondhollow structure 12 is formed such that a corner portion 13 is directedtoward the lower surface, and a partial circumference 14 composed of oneside surface faces the upper surface.

The partial circumferences 14 of the first hollow structures 11 adjacentto each other are connected together in a substantially-horizontal stateby bonding, and the partial circumferences 14 of the second hollowstructures 12 adjacent to each other are similarly connected together bybonding. The first and second hollow structures 11, 12 adjacent to eachother have common side walls 15, which form each corner portion 13 ofthe adjacent first and second hollow structures. Thus, the connectedhollow structure 1 has a substantially-horizontal upper surface and acorrugated lower surface on the whole, and takes a shape resembling aunicursal figure in section.

The connected hollow structure 1 in this embodiment is fabricated asfollows. Firstly, while a sheet (not shown) of a predetermined width isbeing delivered, convex folds and concave folds are sequentially formedon the sheet at intervals according to the size of the hollow structures11, 12 in a required order, and the required surface of the sheet iscoated with glue along the folds.

Subsequently, while the sheet is being folded along the folds so as tostart the folding of the sheet according to the direction as shown by anarrow i in FIG. 45, the required edges of the hollow structures arebonded together, and the sheet is cut.

In comparison with the connected hollow structure in the firstembodiment, the connected hollow structure 1 in the thirty-fourthembodiment shows lower withstanding strength against a planar force,while it shows far more flexible elasticity, since, when the connectedhollow structure is exposed to a planar force of not less than apredetermined value, the hollow structures 11, 12 are largelytransformed and absorb such a planar force.

In particular, since the partial circumference 14 on the lower side ofeach first hollow structure 11 is composed of two uniformly-projectingside surfaces, the connected hollow structure in this embodiment showshighly cushioning properties due to transforming and restoring action ofthese side surface portions.

Thus, the connected hollow structure in this embodiment is suitable foruse as a cushioning material for packaging, and as other packagingmembers for keeping or packaging linear fluorescent lamps or likearticles by inserting such articles into the hollow portions of thehollow structures 11.

(Thirty-fifth embodiment)

FIG. 46 shows a connected hollow structure 1 in a thirty-fifthembodiment as being formed such that while a single sheet a is beingfolded, first hollow structures 11 of a right-angled triangular sectionand of the same size, and second hollow structures 12 of a pentagonalsection including a corner portion 13 formed at the same angle as acorner portion 13 of each first hollow structure 11 are alternatelyarranged in an alternately inverse position as shown in FIG. 46, and thepartial circumferences 14 of the hollow structures 11 and those of thehollow structures 12 are respectively connected together by bonding.

The connected hollow structure 1 has a substantially-horizontal lowersurface formed by connecting the partial circumferences 14 of the firsthollow structures 11 together, and a corrugated upper surface formed byconnecting the partial circumferences of the second hollow structures 12together.

The connected hollow structure 1 in this embodiment shows flexibleelasticity, since the partial circumference 14 on the upper side of eachsecond hollow structure 12 is composed of two side surfaces forming anangular projection, and these side surface portions are smoothlytransformed or restored.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the thirty-fifth embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Thirty-sixth embodiment)

FIG. 47 shows a connected hollow structure 1 in a thirty-sixthembodiment as being formed such that while a single sheet a is beingfolded, first hollow structures 11 of an isosceles triangular sectionand of the same size, and second hollow structures 12 of a pentagonalsection including a corner portion 13 formed at the same angle as acorner portion 13 of each first hollow structure 11 are alternatelyarranged in alternately inverted positions as shown in FIG. 47, and thepartial circumferences 14 of the first hollow structures 11 and those ofthe second hollow structures 12 are respectively connected together bybonding.

The connected hollow structure 1 has a substantially-horizontal lowersurface formed by connecting the partial circumferences 14 of the firsthollow structures 11 together, and a corrugated upper surface formed byconnecting the partial circumferences 14 of the second hollow structures12 together.

In this embodiment, the connected hollow structure is formed such thateach second hollow structure 12 has a pentagonal section, and thepartial circumference 14 of each second hollow structure has atrapezoidal shape composed of three side surfaces and projects upwards,differently from the connected hollow structure 1 in the firstembodiment.

The connected hollow structure 1 in this embodiment shows flexibleelasticity, since the partial circumference 14 on the upper side of eachsecond hollow structure 12 is composed of two side surfaces forming anangular projection, and these side surface portions are smoothlytransformed or restored when the connected hollow structure is exposedto a planar force.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the thirty-sixth embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Thirty-seventh embodiment)

FIG. 48 partially shows a connected hollow structure 1 in athirty-seventh embodiment as being formed such that a large number offirst hollow structures 11 of a regular hexagonal section including acorner portion 13 directed toward the upper surface and a partialcircumference 14 composed of two side surfaces opposite to the cornerportion and facing the lower surface, and a large number of secondhollow structures 12 of an isosceles triangular section including acorner portion 13 directed toward the lower surface and a partialcircumference 14 composed of a side surface opposite to the cornerportion and facing the upper surface are alternately arranged.

The side walls 15 b, which are overlapped with each other in a verticalposition, of the first hollow structures 11, 11 adjacent to each otherare connected together by bonding, and the second hollow structures 12,12 adjacent to each other are connected together by bonding in a portionof the corner portion 13 of each first hollow structure 11 adjacent tothese hollow structures 12, 12. The first and second hollow structures11, 12 adjacent to each other have common side walls, which form thecorner portion 13 of each second hollow structure 13.

The connected hollow structure in this embodiment is fabricated asfollows. Firstly, while a sheet (not shown) of a predetermined width isbeing delivered, convex folds and concave folds are sequentially formedon the sheet in a required order at intervals according to the size ofthe hollow structures 11, 12, and the required surface of the sheet iscoated with glue along the folds.

Subsequently, while the sheet is being folded along the folds torepeatedly form the hollow structures 11 and the adjacent hollowstructures 12 50 as to start the folding of the sheet according to thedirection as shown in an arrow p in FIG. 48, the required portions ofthe hollow structures 11, 12 are bonded together, and the sheet is cut.

According to the above procedure, it is possible to form the connectedhollow structure 1, which is comprised of a single sheet so as to take ashape resembling a unicursal figure in section, and is substantiallyuniform in apparent thickness T, as shown in FIG. 48.

In comparison with the connected hollow structure in the firstembodiment, the connected hollow structure 1 in the thirty-seventhembodiment shows lower withstanding strength against a planar force,while it shows more flexible elasticity, since, when the connectedhollow structure is exposed to a planar force of not less than apredetermined value, the partial circumference 14 composed of two sidesurfaces projecting substantially uniformly downwards in each hollowstructure 11 is transformed and absorbs such a planar force.

Thus, the connected hollow structure 1 in this embodiment is suitablefor use as a cushioning material for packaging, and may be suitably usedfor keeping or packaging linear fluorescent lamps or like articles byinserting such articles into the hollow structures 11, 12.

Further, the connected hollow structure 1 in this embodiment may berounded into a cylindrical shape with the hollow structures 11 turned tothe inside, since, when the connected hollow structure is exposed to anexternal force sideways, the hollow structures 11 of the hexagonalsection are easily transformed in the folding direction.

Other respects of the constitution, functions and effects of theconnected hollow structure in the thirty-seventh embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Thirty-eighth embodiment)

FIG. 49 partially shows a connected hollow structure 1 in athirty-eighth embodiment as being formed such that first hollowstructures 11 of the same size and of a regular pentagonal section, andsecond hollow structures 12 of the same size and of a section equal tothat of the first hollow structures are alternately arranged inalternately inverted positions.

Each first hollow structure 11 is formed such that a corner portion 13is directed toward the upper surface, and a partial circumference 14composed of three side surfaces uniformly projecting downwards faces thelower surface. Each second hollow structure 12 is formed such that acorner portion 13 is directed toward the lower surface, and a partialcircumference 14 composed of three side surfaces uniformly projectingupwards faces the upper surface.

The first hollow structures 11, 11 adjacent to each other are connectedtogether by bonding in a portion of the corner portion 13 of each secondhollow structure 12 positioned between the first hollow structures, andthe second hollow structures 12, 12 adjacent to each other are connectedtogether by bonding in a portion of the corner portion 13 of each firsthollow structure 11 positioned between the second hollow structures.

The first and second hollow structures 11, 12 adjacent to each otherhave common side walls 15, which form the corner portion 13 of each ofthe first and second hollow structures.

The connected hollow structure 1 in the thirty-eighth embodiment isfabricated as follows. Firstly, while a sheet (not shown) of apredetermined width is being delivered, convex folds and concave foldsare sequentially formed on the sheet in a required order at intervalsaccording to the size of the hollow structures 11, 12, and the requiredsurface of the sheet is coated with glue along the folds.

Subsequently, while the sheet is being folded along the folds torepeatedly form the first hollow structures 11 and the adjacent secondhollow structures 12 so as to start the folding of the sheet accordingto the direction of an arrow n in FIG. 49, the required portions of thehollow structures 11, 12 are bonded together, and the sheet is cut.

According to the above procedure, it is possible to form the connectedhollow structure 1, which is comprised of a single sheet so as to take ashape resembling a unicursal figure in section, with a substantiallyuniform apparent thickness T, and with no overlap of the sheet materialof the connected hollow structure, on any surfaces of the hollowstructures 11, 12.

In comparison with the connected hollow structure in the firstembodiment, the connected hollow structure 1 in the thirty-eighthembodiment shows lower withstanding strength against a planar force,while it shows more flexible elasticity, since, when the connectedhollow structure receives a planar force of not less than apredetermined value, the hollow structures 11, 12 are easily transformedand absorb such a force.

Thus, the connected hollow structure in this embodiment is suitable foruse as a cushioning material for packaging, and may be suitably used forkeeping or packaging linear fluorescent lamps or like articles byinserting such articles into the hollow structures 11, 12.

Other respects of the constitution, functions and effects of theconnected hollow structure in the thirty-eighth embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Thirty-ninth embodiment)

FIG. 50 partially shows a connected hollow structure 1 in a thirty-ninthembodiment as being formed such that a large number of first hollowstructures 11 of a quadrangular (or parallelogram) section and of thesame size, and a large number of second hollow structures 12 of the samesize and equal in sectional shape to the first hollow structures arealternately arranged in alternately inverted positions.

Each first hollow structure 11 is formed such that a corner portion 13is directed toward the upper surface, and a partial circumference 14,composed of two side surfaces uniformly projecting downwards, faces thelower surface. On the other hand, each second hollow structure 12 isformed such that a corner portion 13 is directed toward the lowersurface, and a partial circumference 14 composed of two side surfacesuniformly projecting upwards faces the upper surface.

The first hollow structures 11, 11 adjacent to each other are connectedtogether by bonding in a portion of the corner portion 13 of each secondhollow structure 12 positioned between the first hollow structures, andthe second hollow structures 12, 12 adjacent to each other are connectedtogether by bonding in a portion of the corner portion of each firsthollow structure 11 positioned between the second hollow structures.

The connected hollow structure 1 in the thirty ninth embodiment isfabricated as follows. Firstly, while a sheet (not shown) of apredetermined width is being delivered, convex folds and concave foldsare sequentially formed on the sheet in a required order at intervalsaccording to the size of the hollow structures 11, 12, and the requiredsurface of the sheet is coated with glue along the folds.

Subsequently, while the sheet is being folded along the folds so as tostart the folding of the sheet according to the direction shown by anarrow K in FIG. 50, the required portions of the hollow structures 11,11 and those of the second hollow structures 12, 12 are bonded together,and the sheet is cut.

According to the above procedure, it is possible to form the connectedhollow structure 1, which is comprised of a single sheet so as to take ashape resembling a unicursal figure in section, and has no overlapportion of the sheet material of the connected hollow structure on anysurfaces of the hollow structures 11, 12.

In comparison with the connected hollow structure 1 in the firstembodiment, the connected hollow structure 1 in the thirty-ninthembodiment shows far lower withstanding strength against a planar force,while it shows extremely flexible elasticity, since, when the connectedhollow structure receives a planar force of not less than apredetermined value, the hollow structures 11, 12 are easily transformedin the folding direction and absorb such a force.

Thus, the connected hollow structure in this embodiment is suitable foruse as a cushioning material for packaging, and may be suitably used forkeeping or packaging linear fluorescent lamps or like articles byinserting such articles into the hollow structures 11, 12.

The connected hollow structure 1 in this embodiment may be handled in aflatly-folded state on the whole for storage or transportation, sincethe hollow structures 11, 12 have a quadrangular or parallelogramsection, and are connected together in the portions of their cornerportions 13.

Further, the connected hollow structure I in this embodiment may beeasily rounded into a cylindrical shape with the hollow structures 11 or12 turned to the inside, since the hollow structures 11, 12 of thisconnected hollow structure 1 are easily transformed as described above.

Other respects of the constitution, functions, and effects of theconnected hollow structure in the thirty-ninth embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Fortieth embodiment)

FIG. 51 partially shows a connected hollow structure 1 in a fortiethembodiment as being formed such that a large number of first hollowstructures 11 of a regular hexagonal section including a corner portion13 directed toward the upper surface and a partial circumference 14composed of two side surfaces on the opposite side to the corner portionand facing the lower surface, and a large number of second hollowstructures 12 equal in shape and size to the first hollow structures 11and including a corner portion 13 directed toward the lower surface anda partial circumference 14 composed of two side surfaces on the oppositeside to the corner portion and facing the upper surface are alternatelyarranged.

The side walls 15 b, which are overlapped with each other in a verticalposition, of the first hollow structures 11, 11 adjacent to each otherand those of the second hollow structures 12, 12 adjacent to each otherare respectively connected together by bonding. The first and secondhollow structures 11, 12 adjacent to each other have common side walls15, which form the corner portion 13 of each of the first and secondhollow structures.

The connected hollow structure 1 in the fortieth embodiment isfabricated as follows. Firstly, while a sheet (not shown) of apredetermined width is being delivered, convex folds and concave foldsare sequentially formed on the sheet in a required order at intervalsaccording to the size of the hollow structures 11, 12, and the requiredsurface of the sheet is coated with glue along the folds.

Subsequently, while the sheet is being folded along the folds torepeatedly form the first hollow structures 11 and the adjacent secondhollow structures 12 in an alternate arrangement so as to start thefolding of the sheet according to the direction as shown by an arrow min FIG. 51, the required portions of the hollow structures 11, 12 arebonded together, and the sheet is cut.

According to the above procedure, it is possible to form the connectedhollow structure 1 which is comprised of a single sheet so as to take ashape resembling a unicursal figure in section, as shown in FIG. 51.

In comparison with the connected hollow structure in the firstembodiment, the connected hollow structure 1 in the fortieth embodimentshows far lower withstanding strength against a planar force, while itshows more flexible elasticity, since, when the connected hollowstructure receives a planar force of not less than a predeterminedvalue, the partial circumference 14 composed of twosubstantially-uniformly projecting side surfaces in each of the hollowstructures 11, 12 is easily transformed and absorbs such a force.

Thus, the connected hollow structure in this embodiment is suitable foruse as a cushioning material for packaging, and may be suitably used forkeeping or packaging linear fluorescent lamps or like articles byinserting such articles into the hollow structures 11, 12.

The connected hollow structure 1 in this embodiment is handled in aflatly-folded state for storage or transportation, since the hollowstructures 11, 12 have a regular hexagonal section and are flatlyfolded, when the connected hollow structure is exposed to an externalforce sideways.

Further, the connected hollow structure 1 in this embodiment may berounded into a cylindrical shape with the hollow structures 11 or 12turned to the inside, since the hollow structures 11, 12 are easilytransformed in the folding direction when the connected hollow structureis exposed to the external force sideways, as described above.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the fortieth embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Forty-first embodiment)

FIG. 52 partially shows a connected hollow structure 1 in a forty-firstembodiment as being formed such that a large number of first hollowstructures 11 of an isosceles triangular section and of the same sizeand a large number of second hollow structures equal in sectional shapeand size to the first hollow structures are connected together in analternate arrangement. The connected hollow structure in this embodimentis substantially similar in end face structure of the hollow portion tothe connected hollow structure in the first embodiment.

The connected hollow structure 1 has a doughnut-like or sectorial planeon the whole, since the hollow structures 11,12 as the components of theconnected hollow structure 1 are formed such that their sectional sizeis gradually reduced from one end to the other. The connected hollowstructure in this embodiment is different from the connected hollowstructure 1 in the first embodiment in this respect.

(Forty-second embodiment)

FIG. 53 partially shows a connected hollow structure 1 in a forty-secondembodiment as being formed such that first hollow structures 11 of anisosceles triangular section and of the same size, other than thosepositioned on both ends of the connected hollow structure, and secondhollow structures 12 equal in sectional shape and size to the firsthollow structures are alternately arranged in alternately invertedpositions. The second hollow structure 12 at each end of the connectedhollow structure 1 has a right-angled triangular section so as to sharein common an inclined side wall 15 of the adjacent first hollowstructure 11.

A stripe of bending node 15 c consisting of a small groove is formed atthe same level position on one surface of each side wall 15 common tothe hollow structures 11, 12 so as to extend in the lengthwise directionof the hollow structures 11, 12.

When the connected hollow structure 1 in this embodiment receives aplanar force of not less than a predetermined value, the side walls 15of the hollow structures 11, 12 are bent along the nodes 15 c as shownin FIG. 54, and absorb such a force. Thus, in case of using theconnected hollow structure 1 as a packaging member, when the packagingmember is temporarily exposed to an impact in the direction indicated bya bold arrow in FIG. 54, the side walls are bent and absorb such animpact, so that the packaging member is prevented from collapsing at astroke, and an article to be packaged is also prevented from beingdamaged.

When the connected hollow structure having the bending nodes 15 c formedas the grooves on the side walls 15 as described above is exposed to apredetermined load, the side walls are bent with the grooves turnedtoward the inside as shown in FIG. 54, and therefore, it is possible tocontrol the direction of bending. In the illustrated embodiment, whenthe side walls 15 are bent up to the maximum, portions lower than thebending nodes 15 c of both side walls 15, 15 of the second hollowstructures 12 at both ends of the connected hollow structure areoverlapped with each other in a vertical position, and the verticaloverlap portions bear the action of supports. Thus, the connected hollowstructure, in which the side walls have been bent up to the maximum,shows extremely high withstanding strength against a planar force.

According to this embodiment, the bending nodes 15 c are formed byforming the grooves on either surface of the side walls 15 by means ofpress. Otherwise, since the bending nodes attain the most part of theirpurpose as long as the bending nodes function as bending guides when theside walls 15 are exposed to a load of not less than a predeterminedvalue, the bending nodes are not always formed as grooves. For instance,the side walls 15 may be bent by the bending nodes 15 c formed bypressing the side walls 15 from both sides thereof.

Other respects of the constitution, functions and effects of theconnected hollow structure in the forty-second embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Forty-third embodiment)

FIG. 55 partially shows a connected hollow structure of a forty-thirdembodiment as being substantially similar in basic constitution to theconnected hollow structure in the first embodiment, except that eachside wall 15 common to the hollow structures 11, 12 in the forty-thirdembodiment has a concave portion 15 c slightly bent toward the innerportion of the first or second hollow structure and formed at a certainlevel position of each side wall so as to extend in the lengthwisedirection of the side wall 15.

When the connected hollow structure 1 in this embodiment is exposed to aplanar force of not less than a predetermined value, the concaveportions 15 c function as a guide for bending, and the side walls 15 arebent so as to enlarge a concave angle of each concave portion 15 c andabsorb a shock caused by the planar force.

When the connected hollow structure receives a high planar force, theside walls 15 are further bent, and the portions upper than the concaveportions 15 c of the side walls 15 are overlapped with each other in avertical position, so that the vertical overlap portions bear the actionof supports. Thus, the connected hollow structure 1, in which the sidewalls 15 have been bent up to the maximum, shows extremely highwithstanding strength against a planar force.

(Forty-fourth embodiment)

FIG. 56 partially shows a connected hollow structure 1 in a forty-fourthembodiment as being composed of a large number of first hollowstructures 11 of a transformed hexagonal section and of the same size alarge number of second hollow structures 12 of an isosceles triangularsection and placed above portions between the first hollow structures11, 11 adjacent to each other in an inverse arrangement, and auxiliaryhollow structures 11 b of a parallelogram section and placed below thesecond hollow structures 12 and between the first hollow structures 11,11 adjacent to each other.

The first hollow structures 11, 11 adjacent to each other are connectedtogether by bonding in a portion of the corner portion 13 of each secondhollow structure 12 adjacent to the upper side surfaces of the firsthollow structures, and the lower-side partial circumferences 14 formingthe bottom of the first hollow structures are connected together bybonding.

The upper-side partial circumferences 14 of the second hollow structures12, 12 adjacent to each other are connected together by bonding.

The first and second hollow structures 11, 12 adjacent to each otherhave common side walls 15, which form each corner portion 13 of thefirst and second hollow structures, and the auxiliary and first hollowstructures 11 b, 11 adjacent to each other share in common all the sidewalls, which form each auxiliary hollow structure 11 b.

With the constitution described above, the connected hollow structure 1has concave portions 15 d formed on both sides of the auxiliary hollowstructures 11 b.

The connected hollow structure 1 in the forty-fourth embodiment isfabricated as follows. Firstly, while a sheet (not shown) of apredetermined width is being delivered, convex folds and concave foldsare sequentially formed on the sheet in a required order at intervalsaccording to the size of the hollow structures 11, 11 b, 12, and therequired surface of the sheet 1 is coated with glue along the folds.

Subsequently, while the sheet is being folded along the folds torepeatedly form the hollow structures 11, the adjacent hollow structures12 and the hollow structures 11 b below the hollow structures 12 so asto start the folding of the sheet according to the direction as shown byan arrow q in FIG. 56, the required edges of the hollow structures 11,12 are bonded together, and the sheet is cut.

According to the above procedure, it is possible to form the connectedhollow structure 1, which is comprised of a single sheet so as to take ashape resembling a unicursal figure in section, and has no overlapportion of the sheet material of the connected hollow structure on anyside surfaces of the hollow structures 11, 12, 11 b.

The connected hollow structure 1 in this embodiment shows far lowerwithstanding strength against a planar force, while it shows extremelyflexible elasticity, since, when the connected hollow structure 1 inthis embodiment is exposed to a planar force of not less than apredetermined value, the auxiliary hollow structures 11 b aretransformed so as to be folded, namely, to enlarge the concave angle ofeach concave portion 15 d, and absorb such a force.

Thus, the connected hollow structure 1 in this embodiment is suitablefor use as a cushioning material for packaging, and may be suitably usedfor keeping or packaging linear fluorescent lamps or like articles byinserting such articles into the hollow structures 11.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the forty-fourth embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Forty-fifth embodiment)

FIG. 57 partially shows a connected hollow structure 1 in a forty-fifthembodiment as being comprised of a single sheet and is formed such thata large number of first hollow structures 11 of an isosceles triangularsection and of the same size and a large number of second hollowstructures 12 equal in shape an size to the first hollow structures 11are alternately arranged in inverted positions. The second hollowstructure 12 positioned at each end of the connected hollow structurehas a right-angle triangular section.

The connected hollow structure 1 in this embodiment is substantiallysimilar to the connected hollow structure in the first embodiment in therange of the above constitution.

The connected hollow structure 1 in this embodiment has four smallhollow portions 11 a, 12 a of a rectangular equilateral triangularsection respectively formed in the first and second hollow structures 12by folding a sheet a, in a step of alternately forming the first andsecond hollow structures 11, 12, in alternately inverted positions, byfolding the sheet a.

The connected hollow structure 1 in this embodiment is fabricated asfollows. Firstly, while a sheet (not shown) of a predetermined width isbeing delivered, convex folds and concave folds are sequentially formedon the sheet in a required order at intervals according to the size ofthe first and second hollow structures 11, 12 and also the inner smallhollow portions 11 a, 12 a of these hollow structures, and the requiredsurface of the sheet is coated with glue along the folds.

Subsequently, while the sheet is being folded along the folds so as torepeatedly form the first hollow structures 11 including the smallhollow portions 11 a, and the second hollow structures 12 including thesmall hollow portions 12 a in an alternate arrangement, the requirededges of the hollow structures 11, 12 are bonded together, and the sheetis cut.

According to the above procedure, it is possible to form the connectedhollow structure 1, which is comprised of a single sheet so as to take ashape resembling a unicursal figure in section, and has no overlapportion of the sheet material of the connected hollow structure on anyside surfaces of the first hollow structures 11 including the smallhollow portions 11 a, and the second hollow structures 12 including thesmall hollow portions 12 a.

In comparison with the connected hollow structure in the firstembodiment, the connected hollow structure in the forty-fifth embodimentshows higher withstanding strength against a planar force, since thelarge number of hollow portions having the effect of reinforcing eachother, are formed in two, i.e., upper and lower stages. Further, sincethe hollow portions are formed more densely, the connected hollowstructure in this embodiment is suitable for use as a carrier forcarrying adsorbents In addition, in case of cutting the connected hollowstructure 1 in this embodiment in round slices at a predetermined pitch,a slice of the connected hollow structure is suitable for use as a corematerial of a heat-insulating panel or like hollow panel.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the forty-fifth embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Forty-sixth embodiment)

FIG. 58 partially shows a connected hollow structure 1 in a forty-sixthembodiment as a modification of the connected hollow structure in theforty-fifth embodiment, and each of the first and second hollowstructures 11, 12 respectively has two small hollow portions ha or 12 aof a rectangular equilateral triangular section and a single smallhollow portion ha or 12 a of a parallelogram section.

Other respects of the constitution, functions, and effects of theconnected hollow structure 1 in the forty-sixth embodiment aresubstantially similar to those of the connected hollow structure in theforty-fifth embodiment, and hence, the description thereof will beomitted.

(Forty-seventh embodiment)

FIG. 59 partially shows a connected hollow structure 1 in aforty-seventh embodiment as being formed such that the section of thepartial circumference 14 of each second hollow structure 12 in theconnected hollow structure in the first embodiment is modified into apartial circumference of a circular arc section so as to substantiallyuniformly project upwards.

According to the connected hollow structure in this embodiment formed asdescribed above, when the connected hollow structure 1 with the left andright ends in FIG. 59 constrained is exposed to a planar force of notless than a predetermined value, the circular arc-shaped partialcircumferences 14 forming the upper surface of the second hollowstructures 12 are transformed and restored to absorb such a plainpressure. Thus, in comparison with a connected hollow structure in thefirst embodiment, the connected hollow structure in the forty-seventhembodiment better functions as a cushioning material.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the forty-seventh embodiment aresubstantially similar to those of the connected hollow structure in thefirst embodiment, and hence, the description thereof will be omitted.

(Forty-eighth embodiment)

FIG. 60 partially shows a connected hollow structure 1 in a forty-eighthembodiment as a modification of the connected hollow structure in theforty-seventh embodiment, and the partial circumference 14 on the lowerside of each first hollow structure 11 and that of the partialcircumference 14 on the upper side of each second hollow structure 12are respectively modified into a partial circumference of a circular arcsection so as to substantially uniformly project upwards and downwards,respectively.

The connected hollow structure 1 in this embodiment is superior inelasticity to the connected hollow structure in the forty-seventhembodiment, and therefore, is suitable for use as a cushioning materialfor an article to be packaged, since the partial circumferences 14 ofthe hollow structures 11, 12 project in a circular arc shape.

(Forty-ninth embodiment)

FIG. 61 partially shows a connected hollow structure 1 in a forty-ninthembodiment as another modification of the connected hollow structure inthe forty-seventh embodiment, and the partial circumference 14 on theupper surface of part of second hollow structures (every other secondhollow structure) is modified into a partial circumference of a circulararc section 50 as to substantially uniformly project upwards.

Namely, it is possible to form the connected hollow structure 1 whichshows elasticity according to the purpose as a packaging member byselecting the density of the hollow structures 11 or 12 having thepartial circumferences 14 of the circular-arc section.

(Fiftieth embodiment)

FIG. 62 partially shows a connected hollow structure 1 in a fiftiethembodiment as being formed such that each second hollow structure 12 inthe connected hollow structure in the thirty-eighth embodiment (See FIG.49) is modified into a hollow structure of a sectorial section as shownin FIG. 62, instead of the regular pentagonal section, and the partialcircumference 14 on the upper side of each hollow structure 12 ismodified into a partial circumference of a circular arc section 50 as tosubstantially uniformly project upwards.

The effects of the connected hollow structure 1 in this embodimentattained by forming the second hollow structures 12 having the partialcircumference 14 of the circular arc section as shown in FIG. 62 aresubstantially similar to those of the connected hollow structure in theforty-seventh embodiment.

(Fifty-first embodiment)

FIG. 63 partially shows a connected hollow structure 1 in a fifty-firstembodiment as being formed such that the partial circumference 14 on theupper side of each second hollow structure 12 in the connected hollowstructure in the fifteenth embodiment (See FIG. 27) is modified into apartial circumference of a circular arc section 50 as to substantiallyuniformly project upwards.

In comparison with the connected hollow structure in the fifteenthembodiment, the connected hollow structure 1 in the fifty-firstembodiment formed as described above better functions as a cushioningmaterial, since, when the connected hollow structure 1 with the left andright ends in FIG. 63 constrained is exposed to a planar force of notless than a predetermined value, the circular arc-shaped partialcircumferences 14 forming the upper surface of the second hollowstructures 12 are transformed and restored to absorb such a force.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the fifty-first embodiment aresubstantially similar to those of the connected hollow structure in thefifteenth embodiment, and hence, the description thereof will beomitted.

(Fifty-second embodiment)

FIG. 64 partially shows a connected hollow structure 1 in a fifty-secondembodiment as being formed such that the partial circumference 14 ofeach section hollow structure 12 on the inner side of the connectedhollow structure in the twelfth embodiment (See FIG. 24) is modifiedinto a partial circumference of a circular arc section so as tosubstantially uniformly project toward the inside of the connectedhollow structure.

In comparison with the connected hollow structure in the fifthembodiment, the connected hollow structure 1 in the fifty-secondembodiment formed as described above better functions as a cushioningmaterial, since, when the inner surface of the connected hollowstructure 1 receives a force of not less than a predetermined value, thecircular arc-shaped partial circumferences 14 forming the upper surfaceof the second hollow structures 12 are transformed and restored toabsorb such a force.

(Fifty-third embodiment)

FIG. 65 partially shows a connected hollow structure 1 in a fifty-thirdembodiment as being formed such that the partial circumference 14 ofeach second hollow structure 12 on the inner side of the connectedhollow structure 1 in the twelfth embodiment (See FIG. 24) is modifiedinto a partial circumference of a circular arc section so as tosubstantially uniformly project toward the inner side of the connectedhollow structure.

The connected hollow structure 1 in this embodiment formed as describedabove better functions as a cushioning material, since, when theconnected hollow structure 1 is exposed to a load of not less than apredetermined value in the circumferential or inner peripheraldirection, the circular arc-shaped partial circumferences 14 of thesecond hollow structures 12 are transformed and restored to absorb sucha force.

(Fifty-fourth embodiment)

FIG. 66 partially shows a connected hollow structure 1 in a fifty-fourthembodiment as being formed such that the partial circumference 14 ofeach second hollow structure 12 on the inner side of the connectedhollow structure in the thirteenth embodiment (See FIG. 25) is modifiedinto a partial circumference of a circular arc section so as tosubstantially uniformly project toward the inner side of the connectedhollow structure.

The effect of the connected hollow structure 1 in this embodimentattained by forming the second hollow structures 2 having the partialcircumferences 14 of the circular arc section as shown in FIG. 66 issubstantially similar to that of the connected hollow structure in thefifty-third embodiment.

(Fifty-fifth embodiment)

FIG. 67 partially shows a connected hollow structure 1 in a fifty-fifthembodiment as being formed such that the partial circumference 14 ofeach second hollow structure 12 on the inner side of the connectedhollow structure 1 in the fourteenth embodiment (See FIG. 26) ismodified into a partial circumference of a circular arc section so as tosubstantially uniformly project toward the inner side of the connectedhollow structure.

The effect of the connected hollow structure 1 in this embodimentattained by forming the second hollow structures 12 having the partialcircumferences 14 of the circular arc section as shown in FIG. 67 issubstantially similar to that of the connected hollow structure in thefifty-third embodiment.

(Fifty-sixth embodiment)

FIG. 68 shows a connected hollow structure 1 in a fifty-sixth embodimentas being composed of a large number of connecting sheet portions a14bonded together so as to extend in parallel to each other, and a largenumber of cylindrical hollow structures connected together byrespectively bonding circumferential portions together in the lengthwisedirection in 14:7 joint portions a15 between the connecting adjacentsheet portions a14, a14.

The connected hollow structure 1 having the above-constitution isfabricated as follows. Firstly, while a sheet a (not shown) of apredetermined width is being delivered, convex (or concave) folds aresequentially formed on the sheet a so as to extend in the transversedirection of the sheet a according to the sectional peripheral length ofeach hollow structure and the width of each connecting sheet portiona14, and the fold portions of the sheet are coated with glue.

Subsequently, while the sheet a is being rounded into cylindricalportions from the leading end of the sheet along the folds, the foldscorresponding to the joint portions a15 forming the joints of thecylindrical portions are bonded together. When the connected hollowstructure 1 thus fabricated reaches a predetermined length, the sheet,which is being delivered, is cut.

According to the above procedure, it is possible to form the connectedhollow structure 1, which is comprised of a single sheet so as to take ashape resembling a unicursal figure in section, and has no overlapportion of the sheet material of the connected hollow structure, otherthan the joint portions a15.

The connected hollow structure 1 in this embodiment shows far lowerwithstanding strength against a planar force, while it shows extremelyflexible elasticity, since, when the connected hollow structure receivesa planar force of not less than a predetermined value, the hollowstructures are transformed so as to become flat, and absorb such aforce.

Thus, the connected hollow structure in this embodiment is suitable foruse as a cushioning material for packaging, and may be suitably used forkeeping or packaging linear fluorescent lamps or like articles byinserting such articles into the hollow structures 10.

Since the cylindrical hollow structures 10 are transformed by arelatively small external force, the connected hollow structure 1 in thestate shown in FIG. 68 may be rounded, for instance, in a cylindricalshape with the hollow structures 10 positioned along the inner surface.Thus, such a cylindrical connected hollow structure 1 is suitable foruse as a frame structure for encasing bottles or like articles.

When a corrugated fiberboard is used for forming the connected hollowstructure 1 in this embodiment, the folds are preferably formed inparallel to flutes of the corrugated fiberboard. Further, the hollowstructures 10 preferably have a cylindrical or elliptical section.

(Fifty-seventh embodiment)

FIG. 69 partially shows a connected hollow structure 1 in afifty-seventh embodiment as a modification of the connected hollowstructure in the fifty-sixth embodiment, and is designed such that thehollow structures 10 are formed at slightly wider intervals (i.e., theconnecting sheet portions a15 are formed to be slightly wider). Thus,the connected hollow structure 1 in this embodiment has a cylindricalshape overall with the hollow structures 10 lined up along the innersurface such that the hollow structures 10 are spaced slightly, afterthe connecting sheet portions a15 and the hollow structures 10 have beenformed as one body.

The cylindrical or elliptical hollow structures 10 are easilytransformed when receiving an external force, and therefore, showpreferable effects from the viewpoint of cushioning properties, since,when the connected hollow structure 1 in this embodiment is used as apackaging frame structure for encasing bottles or like articles byinserting such bottles into the connected hollow structure 1 such thatthe hollow structures 10 are slightly compressed by the bottles in thecircumferential direction, the bottles remain held at all times by theaction of a predetermined elastic force.

When a corrugated fiberboard is used for forming the connected hollowstructure 1 in this embodiment, the folds are preferably formed inparallel to flutes of the corrugated fiberboard.

(Fifty-eighth embodiment)

FIG. 70 partially shows a connected hollow structure in a fifty-eighthembodiment as being composed of a large number of mutually adjacenthollow structures 10 connected together, and the hollow structures 10include first hollow structures 10 lib of a substantially drop-shapedsection and second hollow structures 12 b of a substantially inversedrop-shaped section.

The first and second hollow structures 11 b, 12 b are formed in analternate arrangement by processing a sheet so as to sequentially formportions a16 of the sectional shape of a letter S and portions a17 ofthe sectional shape of an inverse letter S in an alternate arrangement,and then connecting together the side of each portion 16 a of thesectional shape of the letter S with the side of the adjacent portiona17 of the sectional shape of the inverse letter S.

Since the connected hollow structure 1 in this embodiment is comprisedof a single sheet so as to take the shape resembling a unicursal figurein section, and has no overlap of the sheet material in the connectedhollow structure, other than the joint portions between each portion ofthe sectional shape of the letter S and the adjacent portion of thesectional shape of the inverse letter S, the apparent specific gravityof this connected hollow structure is extremely small.

The connected hollow structure 1 in this embodiment shows extremely lowwithstanding strength against a planar force, while it shows extremelyflexible elasticity, since, when the hollow structures 11 b, 12 breceive an external force, the hollow structures 11 b, 12 b aretransformed and absorb such a force.

Thus, the connected hollow structure 1 in this embodiment is suitablefor use as a cushioning material for packaging, and may be suitably usedfor keeping or packaging linear fluorescent lamps or like articles byinserting such articles into the hollow structures 11 b, 12 b.

The connected hollow structure in this embodiment may be also used forpackaging bottles or like articles having a cylindrical portion byrounding this connected hollow structure into a cylindrical shape withthe hollow structures 11 b or 12 b turned toward the inner side, sincethe hollow structures 11 b, 12 b are easily transformed by receipt of anexternal force.

When a corrugated fiberboard is used for forming the connected hollowstructure 1 in this embodiment, the folds are preferably formed inparallel with the flutes of the corrugated fiberboard.

Other functions and effects of the connected hollow structure 1 in thefifty-eighth embodiment are substantially similar to those of theconnected hollow structure in the first embodiment, and hence, thedescription thereof will be omitted.

(Fifty-ninth embodiment)

FIG. 71 shows a connected hollow structure 1 in a fifty-ninth embodimentas basically similar to the connected hollow structure in thefifty-eighth embodiment, except that the connected hollow structure inthe fifty-ninth embodiment has a cylindrical shape overall and thesecond hollow structures 12 b of this connected hollow structure aresmaller in peripheral length than the first hollow structures 11 b.

The connected hollow structure 1 in this embodiment shows extremelyflexible elasticity, since, when the connected hollow structure 1receives an external force, the hollow structures 11 b, 12 b aretransformed and absorb such a force.

The connected hollow structure 1 in this embodiment is suitably used forpackaging bottles or like articles having a cylindrical portion byinserting such articles into the connected hollow structure, or keepingor packaging linear fluorescent lamps or like articles by inserting sucharticles into the connected hollow structure.

Other functions and effects of the connected hollow structure in thefifty-ninth embodiment are substantially similar to those of theconnected hollow structure in the fifty-eighth embodiment, and hence,the description thereof will be omitted.

(Sixtieth embodiment)

FIG. 72 shows a connected hollow structure 1 in a sixtieth embodiment asbeing formed such that a large number of hollow structures 10, eachformed by symmetrically combining a first hollow portion 10 a of anangular section and a second hollow portion 10 b of an inverse angularsection, are arranged densely in parallel to each other, and the hollowstructures adjacent to each other are connected together in shape of aletter S or an inverse letter S in section.

The first hollow portions 10 a in this embodiment have a semicircularsection, and the second hollow portions 10 b have a semicircular sectionreverse to that of the first hollow portions 10 a.

The connected hollow structure 1 in this embodiment is suitable for useas a packaging member as a cushioning material for articles to bepackaged, and as other packaging members for protecting linearfluorescent lamps or like rod-shaped or cylindrical articles byinserting such articles into the hollow portions 10 a, 10 b, since thehollow structures 10 including the hollow portions 10 a, 10 b showflexible elasticity.

Further, when the connected hollow structure 11 having more hollowstructures 10 is rounded into a cylindrical shape, the hollow portionspositioned on the cylindrically inner surface are compressivelytransformed to easily form a cylindrical connected hollow structure.Thus, such a cylindrical connected hollow structure is suitable for useas a packaging member for protecting bottles or like articles to bepackaged.

Incidentally, when a corrugated fiberboard is used as a sheet forforming the connected hollow structure, the hollow structures arepreferably formed in parallel to flutes of the corrugated fiberboard(not shown).

(Sixty-first embodiment)

FIG. 73 shows a connected hollow structure 1 in a sixty-first embodimentas being formed such that the first and second hollow portions 10 a, 10b included in the hollow structures in the connected hollow structure inthe sixtieth embodiment are respectively modified into hollow portionsof a trapezoidal section and an inverse trapezoidal section.

The other respects of the constitution, functions and effects of theconnected hollow structure 1 in the sixty-first embodiment aresubstantially similar to those of the connected hollow structure in thesixtieth embodiment, and hence, the description thereof will be omitted.

(Sixty-second embodiment)

FIG. 74 shows a connected hollow structure 1 in a sixty-secondembodiment as being formed such that the first and second hollowportions 10 a, 10 b included in the hollow structures in the connectedhollow structure in the sixtieth embodiment are respectively modifiedinto hollow portions of a triangular section and an inverse triangularsection.

Other respects of the constitution, functions and effects of theconnected hollow structure 1 in the sixty-second embodiment aresubstantially similar to those of the connected hollow structure in thesixtieth embodiment, and hence, the description thereof will be omitted.

(Other embodiments)

In the connected hollow structure 1 in the twenty-fourth embodiment asshown in FIG. 36 according to the present invention, the second hollowstructures 12 may have a quadrangular (parallelogram) section, insteadof a triangular section. The connected hollow structure having thesecond hollow structures 12 of the quadrangular section as describedabove forms a connected hollow structure.

In the connected hollow structure 1 in the OS twelfth embodiment asshown in FIGS. 23 and 24, and that in the thirteenth embodiment as shownin FIG. 25 according to the present invention, the partial circumference14 of each first hollow structure 11 maybe composed of a plurality ofsubstantially uniformly projecting side surfaces, similarly to thepartial circumference 14 of each first hollow structure 11 in theconnected hollow structure 1 shown in FIG. 67, for instance.

In the connected hollow structure 1 in the fifteenth embodiment as shownin FIG. 27, that in the thirty-second embodiment as shown in FIG. 43 andthat in the thirty-third embodiment as shown in FIG. 44 according to thepresent invention, the partial circumference 14 of each second hollowstructure 12 may be composed of a plurality of substantially uniformlyprojecting side surfaces, similarly to the partial circumference 14 ofeach second hollow structure 12 in the connected hollow structure 1 asshown in FIGS. 46 and 47, for instance.

In the connected hollow structure 1 in the sixteenth embodiment as shownin FIG. 28 according to the present invention, the partial circumference14 of each second hollow structure may be composed of a plurality ofsubstantially uniformly projecting side surfaces, similarly to thepartial circumference 14 of each second hollow structure 12 in theconnected hollow structure 1 as shown in FIGS. 46 and 47, for instance.

(Capability of Industrial Utilization)

The connected hollow structure and packaging member according to thepresent invention is useful as a protection frame structure forpackaging, a cushioning material for packaging, a carrying tray, a corematerial for a heat-insulating panel or other hollow panels, a wallmaterial, a pallet and a carrier for carrying adsorbents.

What is claimed is:
 1. A corrugated sheet packaging material formed of asingle paper or corrugated fiberboard sheet folded into an array ofalternating first and second hollow structures extending parallel to thefolds in a longitudinal direction, said sheet packaging material havingfirst and second opposing surfaces; wherein each of said first andsecond hollow structures has at least first, second and third side wallsjoined at corners to define a closed polygon in cross-sectionperpendicular to the longitudinal direction; wherein each of said firsthollow structures has its first and second side walls meeting at one ofsaid corners and at least in part shared in common with adjacent secondhollow structures, said third side walls of said first hollow structuresbeing connected together to form said first opposing surface and saidone corner being located at said second opposing surface; wherein eachof said second hollow structures has its first and second side wallsmeeting at a second of said corners and at least in part shared incommon with adjacent first hollow structures, said third side walls ofsaid second hollow structure being connected together to form saidsecond opposing surface and said second corners being located at saidfirst opposing surface; and wherein at least a portion of said thirdsides of said second hollow structures are convex circular arcs formingprotuberances at said second opposing surface.
 2. A corrugated sheetpackaging material according to claim 1 wherein said first and secondopposing surfaces are parallel so that said corrugated sheet packagingmaterial has a substantially uniform thickness.
 3. A corrugated sheetpackaging material according to claim 1 wherein said first and secondopposing surfaces gradually diverge in a direction perpendicular to saidlongitudinal direction.
 4. A corrugated sheet packaging materialaccording to claim 1 wherein said first opposing surface is planar.
 5. Acorrugated sheet packaging material according to claim 1 wherein atleast a portion of said third sides of said first hollow structures areconvex circular arcs forming protuberances at said first opposingsurfaces.
 6. A corrugated sheet packaging material according to claim 1wherein said third side walls and fourth side walls of said first hollowstructures extend beyond said second corners to form protuberances onsaid first opposing surface.
 7. A corrugated sheet packaging materialformed of a single paper or corrugated fiberboard sheet folded into anarray of alternating first and second hollow structures extendingparallel to the folds in a longitudinal direction, said sheet packagingmaterial having first and second opposing surfaces; wherein each of saidfirst and second hollow structures has side walls joined at corners todefine closed polygons in cross-section perpendicular to thelongitudinal direction; wherein each of said first hollow structures hasa pair of said side walls meeting at one of said corners and shared incommon with adjacent second hollow structures, said one corner definingsaid first opposing surface; and wherein each of said second hollowstructures has first and second of said side walls meeting at a secondof said corners and shared in common with adjacent first hollowstructures and at least third and fourth of said side walls extendingfrom said first opposing surface to form protuberances thereon.
 8. Acorrugated sheet packaging material according to claim 7 wherein each ofsaid first hollow structures has an additional one of said side wallsopposite said one corner, said additional side walls being joinedtogether to form said second opposing surface as a planar surface.
 9. Acorrugated sheet packaging material according to claim 7 wherein saidthird and fourth side walls join at one of said corners.
 10. Acorrugated sheet packaging material according to claim 7 wherein each ofsaid second hollow structures has a fifth of said side walls joiningsaid third and fourth side walls.
 11. A corrugated sheet packagingmaterial according to claim 7 wherein said second corners define saidsecond opposing surface and wherein each of said first hollow structureshas at least two additional side walls extending from said secondopposing surface to form protuberances thereon.
 12. A corrugated sheetpackaging material according to claim 11 wherein said first and secondhollow structures are square, rectangular or hexagonal in cross-section.13. A corrugated sheet packaging material according to claim 7 whereinsaid first and second opposing surfaces are parallel so that saidcorrugated sheet packaging material has a substantially uniformthickness.
 14. A corrugated sheet packaging material formed of a singlepaper or corrugated fiberboard sheet folded into an array of alternatingfirst and second hollow structures extending parallel to the folds in alongitudinal direction, said sheet packaging material having first andsecond opposing surfaces; wherein each of said first and second hollowstructures has at least first, second and third side walls joined atcorners to define a closed polygon in cross-section perpendicular to thelongitudinal direction; wherein each of said first and second hollowstructures has its first and second side walls meeting at one of saidcorners and at least in part shared in common with adjacent ones of saidhollow structures; wherein third side walls of said first hollowstructures are connected together to form said first opposing surfaceand third side walls of said second hollow structures are connectedtogether to form said second opposing surface; and wherein each of saidfirst and second side walls has a bending node formed therein forbending of said first and second walls at said bending node responsiveto application of a force on said opposing surfaces.
 15. A corrugatedsheet packaging material according to claim 14 wherein the closedpolygon of the cross-section of each of said first and second hollowstructures is a triangle and wherein said first and second opposingsurfaces are parallel so that said corrugated sheet packaging materialhas a substantially uniform thickness.
 16. A corrugated sheet packagingmaterial according to claim 14 wherein said bending node is a grooveformed in said first and second side walls and extending in thelongitudinal direction.
 17. A corrugated sheet packaging materialaccording to claim 14 wherein said bending node is a bend formed in saidfirst and second side walls and extending in the longitudinal direction.18. A corrugated sheet packaging cylinder having exterior and interiorcylindrical surfaces and formed of a single paper or corrugatedfiberboard sheet folded to form first and second hollow structuresarranged alternating around the circumference of the cylinder, saidhollow structures extending parallel to the central axis of the cylinderin a longitudinal direction, wherein each of said first hollowstructures has side walls joined at corners to define a closed polygonin cross-section perpendicular to the longitudinal direction, said sidewalls including a pair of side walls meeting at one of said corners andshared in common with said second hollow structures; wherein each ofsaid second hollow structures has side walls joined at corners to definea closed polygon in cross-section perpendicular to the longitudinaldirection; and wherein first side walls of said first hollow structurestogether define the interior cylindrical surface as having across-section which is polygonal and close to circular and first sidewalls of said second hollow structures together define the exteriorcylindrical surface as having a cross-section which is square withchamfered corners.
 19. A corrugated sheet packaging cylinder accordingto claim 18 wherein said polygons are different triangles and whereinsaid first side walls are bases of said triangles.
 20. A corrugatedsheet packaging cylinder according to claim 19 wherein the bases of thetriangles of said first hollow structures are convex circular arcsforming protuberances on said inner cylindrical surface.
 21. Acorrugated sheet packaging cylinder according to claim 18 wherein saidside walls of said first hollow structures include additional side wallsextending from said inner polygonal cylindrical surface to formprotuberances thereon.
 22. A corrugated sheet packaging cylinderaccording to claim 18 wherein said first side walls of said first hollowstructures are convex circular arcs forming protuberances on said innercylindrical surface.
 23. A corrugated sheet packaging cylinder accordingto claim 22 wherein said first side walls of said second hollowstructures are connected together.
 24. A corrugated sheet packagingcylinder formed of a single sheet of paper or corrugated fiberboardfolded into an array of parallel hollow structures which are circular orellipsoidal in cross-section and which extend in parallel along onedimension of corrugated sheet packaging material, with interveningsections of said sheet joining said hollow structures together anddefining one surface of said corrugated packaging material.
 25. Acorrugated packaging material according to claim 24 formed into acylinder having said one surface as its external surface.
 26. Acorrugated packaging material formed of a single sheet of paper orcorrugated fiberboard folded into a parallel array of alternating firstand second hollow structures having a closed drop-shaped cross-sectionand sharing side wall portions in common, adjacent first hollowstructures being attached at points of maximum dimension across saiddrop-shaped cross-section and adjacent second hollow structures beingattached at points of maximum dimension across said drop-shapedcross-section.
 27. A corrugated packaging material according to claim 26formed into a cylinder.
 28. A corrugated packaging material formed of asheet of paper or corrugated fiberboard folded into an array of parallelhollow structures with a fold of said sheet bisecting each of saidhollow structures into two symmetrical sections.
 29. A corrugatedpackaging material according to claim 28 wherein said symmetricalsections are semicircular, trapezoidal or triangular in cross-section.30. A channel-shaped corrugated packaging material formed as a sheet ofpaper or corrugated fiberboard folded into parallel and alternatingfirst and second hollow structures extending in a longitudinaldirection, said hollow structures arranged to form a pair of parallelside members connected by a planar member; wherein each of said firstand second hollow structures has side walls joined at corners to definea closed polygon in cross-section perpendicular to the longitudinaldirection; wherein each of said first hollow structures has a pair ofsaid side walls meeting at one of said corners and at least in partshared in common with adjacent second hollow structures; and whereineach of said second hollow structures has first and second of said sidewalls meeting at a second of said corners and at least in part shared incommon with adjacent first hollow structures.
 31. A channel-shapedcorrugated sheet packaging material according to claim 30 wherein saidparallel side members have chamfered edges sloping inwardly toward saidplanar member.
 32. A corrugated packaging material formed of a singlesheet of paper or corrugated fiberboard folded into plural linear arraysof parallel alternating first and second hollow structures extending ina longitudinal direction, one of said plural arrays forming a bottomplanar member, a second of said plural arrays forming a first sidemember extending at a right angle from said bottom planar member and athird of said plural arrays forming a second side member extending at aright angle from said bottom planar member and at a right angle fromsaid first side member; wherein said bottom planar member and said firstand second side members define an interior for said corrugated packagingmaterial; and wherein each of said first and second hollow structureshas side walls joined at corners to define a closed polygon incross-section perpendicular to the longitudinal direction; wherein eachof said first hollow structures has a pair of said side walls meeting atone of said corners and at least in part shared in common with adjacentsecond hollow structures; and wherein each of said second hollowstructures has first and second of said side walls meeting at a secondof said corners and at least in part shared in common with adjacentfirst hollow structures.
 33. A corrugated packaging material accordingto claim 32 wherein at least a portion of sides of said polygons facingsaid interior are convex circular arcs.
 34. A corrugated packagingmaterial according to claim 33 wherein: the first and second hollowstructures of said first side member are substantially perpendicular tothe first and second hollow structures of said bottom planar member; thefirst and second hollow structures of said second side member areparallel to the first and second hollow structures of said bottom planarmember and perpendicular to the first and second hollow structures ofsaid first side member; and said first and second side members areconnected to said bottom planar member through connecting portions ofsaid single sheet.
 35. A corrugated packaging material according toclaim 32 wherein: the first and second hollow structures of said firstside member are substantially perpendicular to the first and secondhollow structures of said bottom planar member; the first and secondhollow structures of said second side member are parallel to the firstand second hollow structures of said bottom planar member andperpendicular to the first and second hollow structures of said firstside member; and said first and second side members are connected tosaid bottom planar member through connecting portions of said singlesheet.
 36. A corrugated packaging material according to claim 33 whereina fourth or said plural arrays forms a third side member extending at aright angle from said bottom planar member; wherein a fifth of saidplural arrays forms a fourth side member extending at a right angle fromsaid bottom planar member; and wherein said first, second, third andfourth side members are joined to each other at right angles to form, incooperation with said bottom planar member, an open box structure.
 37. Acorrugated packaging material according to claim 36 wherein: the firstand second hollow structures of said first and third side members areperpendicular to the first and second hollow structures of said bottomplanar member; the first and second hollow structures of said second andfourth side members are parallel to the first and second hollowstructures of said bottom planar member and perpendicular to the firstand second hollow structures of said first and second hollow structuresof said first and third side members; and said first, second, third andfourth side members are connected to said bottom planar member throughconnecting portions of said single sheet.
 38. A packaging materialcomprising a corrugated planar member folded into a block structure ofsuperimposed folds, said corrugated planar member being formed of asheet folded into a linear array of alternating first and second hollowstructures extending in parallel to the folds in said sheet and in alongitudinal direction, and said corrugated planar member having firstand second opposing surfaces; wherein each of said first and secondhollow structures has side walls jointed at corners to define a closedpolygon in cross-section perpendicular to the longitudinal direction;wherein each of said first hollow structures has a pair of said sidewalls meeting at one of said corners and shared in common with adjacentsecond hollow structures; and wherein each of said second hollowstructures has first and second of said side walls meeting at a secondof said corners and shared in common with adjacent first hollowstructures.
 39. A packaging material according to claim 38 whereinevenly spaced, parallel cuts are formed in said corrugated planar memberperpendicular to said longitudinal direction, said cuts alternatingbetween said first and second opposing surfaces, said corrugated planarmember being folded at said cuts to form said block structure.